Configuring IEEE 802.1x Port

Configuring IEEE 802.1x Port-Based

Authentication

This chapter describes how to configure IEEE 802.1x port-based authentication. IEEE 802.1x authentication prevents unauthorized devices (clients) from gaining access to the network. Unless otherwise noted, the term

switch refers to a standalone switch or a switch stack.

•

Finding Feature Information, page 1

•

Information About 802.1x Port-Based Authentication, page 1

•

How to Configure 802.1x Port-Based Authentication, page 35

•

Monitoring 802.1x Statistics and Status, page 94

•

Additional References for IEEE 802.1x Port-Based Authentication, page 95

•

Feature Information for 802.1x Port-Based Authentication, page 96

Finding Feature Information

Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the feature information table at the end of this module.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support.

To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn . An account on Cisco.com is not required.

Information About 802.1x Port-Based Authentication

The 802.1x standard defines a client-server-based access control and authentication protocol that prevents unauthorized clients from connecting to a LAN through publicly accessible ports unless they are properly authenticated. The authentication server authenticates each client connected to a switch port before making available any services offered by the switch or the LAN.

Security Configuration Guide, Cisco IOS XE Release 3SE (Catalyst 3850 Switches)

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Configuring IEEE 802.1x Port-Based Authentication

Port-Based Authentication Process

Note

TACACS is not supported with 802.1x authentication.

Until the client is authenticated, 802.1x access control allows only Extensible Authentication Protocol over

LAN (EAPOL), Cisco Discovery Protocol (CDP), and Spanning Tree Protocol (STP) traffic through the port to which the client is connected. After authentication is successful, normal traffic can pass through the port.

The table shown below lists the maximum number of each client session supported on Catalyst 3850 and

Catalyst 3650 switches:

Client session

Maximum dot1x or MAB client sessions

Maximum sessions supported

2000

Maximum web-based authentication sessions 2000

Maximum dot1x sessions with critical-auth VLAN enabled and server re-initialized

2000

Maximum MAB sessions with various session features applied

2000

Maximum dot1x sessions with service templates or session features applied

2000

Note

For complete syntax and usage information for the commands used in this chapter, see the “RADIUS

Commands” section in the Cisco IOS Security Command Reference, Release 3SE


To configure IEEE 802.1X port-based authentication, you must enable authentication, authorization, and accounting (AAA) and specify the authentication method list. A method list describes the sequence and authentication method to be queried to authenticate a user.

The AAA process begins with authentication. When 802.1x port-based authentication is enabled and the client supports 802.1x-compliant client software, these events occur:

• If the client identity is valid and the 802.1x authentication succeeds, the switch grants the client access to the network.

• If 802.1x authentication times out while waiting for an EAPOL message exchange and MAC authentication bypass is enabled, the switch can use the client MAC address for authorization. If the client MAC address is valid and the authorization succeeds, the switch grants the client access to the network. If the client MAC address is invalid and the authorization fails, the switch assigns the client to a guest VLAN that provides limited services if a guest VLAN is configured.

• If the switch gets an invalid identity from an 802.1x-capable client and a restricted VLAN is specified, the switch can assign the client to a restricted VLAN that provides limited services.

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• If the RADIUS authentication server is unavailable (down) and inaccessible authentication bypass is enabled, the switch grants the client access to the network by putting the port in the critical-authentication state in the RADIUS-configured or the user-specified access VLAN.

Note

Inaccessible authentication bypass is also referred to as critical authentication or the

AAA fail policy.

If Multi Domain Authentication (MDA) is enabled on a port, this flow can be used with some exceptions that are applicable to voice authorization.

This figure shows the authentication process.

Figure 1: Authentication Flowchart

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The switch re-authenticates a client when one of these situations occurs:

• Periodic re-authentication is enabled, and the re-authentication timer expires.

You can configure the re-authentication timer to use a switch-specific value or to be based on values from the RADIUS server.

After 802.1x authentication using a RADIUS server is configured, the switch uses timers based on the

Session-Timeout RADIUS attribute (Attribute[27]) and the Termination-Action RADIUS attribute

(Attribute [29]).


3


Port-Based Authentication Initiation and Message Exchange

The Session-Timeout RADIUS attribute (Attribute[27]) specifies the time after which re-authentication occurs.

The Termination-Action RADIUS attribute (Attribute [29]) specifies the action to take during re-authentication. The actions are Initialize and ReAuthenticate. When the Initialize action is set (the attribute value is DEFAULT), the 802.1x session ends, and connectivity is lost during re-authentication.

When the ReAuthenticate action is set (the attribute value is RADIUS-Request), the session is not affected during re-authentication.

• You manually re-authenticate the client by entering the dot1x re-authenticate interface interface-id privileged EXEC command.


During 802.1x authentication, the switch or the client can initiate authentication. If you enable authentication on a port by using the authentication port-control auto interface configuration command, the switch initiates authentication when the link state changes from down to up or periodically as long as the port remains up and unauthenticated. The switch sends an EAP-request/identity frame to the client to request its identity. Upon receipt of the frame, the client responds with an EAP-response/identity frame.

However, if during bootup, the client does not receive an EAP-request/identity frame from the switch, the client can initiate authentication by sending an EAPOL-start frame, which prompts the switch to request the client’s identity.

Note

If 802.1x authentication is not enabled or supported on the network access device, any EAPOL frames from the client are dropped. If the client does not receive an EAP-request/identity frame after three attempts to start authentication, the client sends frames as if the port is in the authorized state. A port in the authorized state effectively means that the client has been successfully authenticated.

When the client supplies its identity, the switch begins its role as the intermediary, passing EAP frames between the client and the authentication server until authentication succeeds or fails. If the authentication succeeds, the switch port becomes authorized. If the authentication fails, authentication can be retried, the port might be assigned to a VLAN that provides limited services, or network access is not granted.

The specific exchange of EAP frames depends on the authentication method being used.

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This figure shows a message exchange initiated by the client when the client uses the One-Time-Password

(OTP) authentication method with a RADIUS server.

Figure 2: Message Exchange

If 802.1x authentication times out while waiting for an EAPOL message exchange and MAC authentication bypass is enabled, the switch can authorize the client when the switch detects an Ethernet packet from the client. The switch uses the MAC address of the client as its identity and includes this information in the

RADIUS-access/request frame that is sent to the RADIUS server. After the server sends the switch the

RADIUS-access/accept frame (authorization is successful), the port becomes authorized. If authorization fails and a guest VLAN is specified, the switch assigns the port to the guest VLAN. If the switch detects an EAPOL packet while waiting for an Ethernet packet, the switch stops the MAC authentication bypass process and starts 802.1x authentication.

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5


Authentication Manager for Port-Based Authentication

This figure shows the message exchange during MAC authentication bypass.

Figure 3: Message Exchange During MAC Authentication Bypass


Port-Based Authentication Methods

Table 1: 802.1x Features

Authentication method Mode

Single host

802.1x

VLAN assignment

Per-user ACL

Filter-ID attribute

Downloadable

ACL

1

Redirect URL

Multiple host

VLAN assignment

MDA Multiple

Authentication

VLAN assignment

Downloadable

ACL

Redirect URL

VLAN assignment

Per-user ACL

Filter-Id attribute

Per-user ACL

Filter-Id attribute

Downloadable

ACL

Redirect URL

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Authentication method Mode

Single host Multiple host MDA

MAC authentication bypass VLAN assignment

Per-user ACL

Filter-ID attribute

Downloadable

ACL

Redirect URL

VLAN assignment

Standalone web authentication Proxy ACL, Filter-Id attribute, downloadable ACL

Multiple

Authentication

VLAN assignment

Per-user ACL

VLAN assignment

Per-user ACL

Filter-Id attribute Filter-Id attribute

Downloadable

ACL

Downloadable

ACL

Redirect URL Redirect URL

NAC Layer 2 IP validation Filter-Id attribute Filter-Id attribute

Downloadable

ACL

Downloadable

ACL


Downloadable

ACL

Downloadable

ACL

Redirect URL Redirect URL Redirect URL Redirect URL

Web authentication as fallback method

2

Proxy ACL Proxy ACL Proxy ACL Proxy ACL


Downloadable

ACL

Downloadable

ACL


Downloadable

ACL

Downloadable

ACL

1 Supported in Cisco IOS Release 12.2(50)SE and later.

2 For clients that do not support 802.1x authentication.

Per-User ACLs and Filter-Ids

Note

You can only set any as the source in the ACL.

Note

For any ACL configured for multiple-host mode, the source portion of statement must be any. (For example,

permit icmp any host 10.10.1.1.)

You must specify any in the source ports of any defined ACL. Otherwise, the ACL cannot be applied and authorization fails. Single host is the only exception to support backward compatibility.

More than one host can be authenticated on MDA-enabled and multiauth ports. The ACL policy applied for one host does not effect the traffic of another host. If only one host is authenticated on a multi-host port, and the other hosts gain network access without authentication, the ACL policy for the first host can be applied to the other connected hosts by specifying any in the source address.

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Port-Based Authentication Manager CLI Commands

The authentication-manager interface-configuration commands control all the authentication methods, such as 802.1x, MAC authentication bypass, and web authentication. The authentication manager commands determine the priority and order of authentication methods applied to a connected host.

The authentication manager commands control generic authentication features, such as host-mode, violation mode, and the authentication timer. Generic authentication commands include the authentication host-mode,

authentication violation, and authentication timer interface configuration commands.

802.1x-specific commands begin with the dot1x keyword. For example, the authentication port-control

auto interface configuration command enables authentication on an interface. However, the dot1x

system-authentication control global configuration command only globally enables or disables 802.1x

authentication.

Note

If 802.1x authentication is globally disabled, other authentication methods are still enabled on that port, such as web authentication.

The authentication manager commands provide the same functionality as earlier 802.1x commands.

When filtering out verbose system messages generated by the authentication manager, the filtered content typically relates to authentication success. You can also filter verbose messages for 802.1x authentication and

MAB authentication. There is a separate command for each authentication method:

• The no authentication logging verbose global configuration command filters verbose messages from the authentication manager.

• The no dot1x logging verbose global configuration command filters 802.1x authentication verbose messages.

• The no mab logging verbose global configuration command filters MAC authentication bypass (MAB) verbose messages

Table 2: Authentication Manager Commands and Earlier 802.1x Commands

The authentication manager commands in Cisco IOS

Release 12.2(50)SE or later authentication

control-direction {both | in}

The equivalent 802.1x

commands in Cisco IOS

Release 12.2(46)SE and earlier

Description dot1x control-direction

{both | in}

Enable 802.1x authentication with the wake-on-LAN (WoL) feature, and configure the port control as unidirectional or bidirectional.

authentication event dot1x auth-fail vlan dot1x critical (interface configuration) dot1x guest-vlan6

Enable the restricted VLAN on a port.

Enable the inaccessible-authentication-bypass feature.

Specify an active VLAN as an 802.1x guest

VLAN.

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Ports in Authorized and Unauthorized States

The authentication manager commands in Cisco IOS

Release 12.2(50)SE or later authentication fallback

fallback-profile

The equivalent 802.1x

commands in Cisco IOS

Release 12.2(46)SE and earlier

Description dot1x fallback

fallback-profile

Configure a port to use web authentication as a fallback method for clients that do not support 802.1x authentication.

authentication host-mode

[multi-auth | multi-domain |

multi-host | single-host]

dot1x host-mode {single-host

| multi-host | multi-domain}

Allow a single host (client) or multiple hosts on an 802.1x-authorized port.

authentication order mab authentication periodic authentication port-control

{auto | force-authorized |

force-un authorized}

dot1x reauthentication

dot1x port-control {auto |

force-authorized |

force-unauthorized}

Provides the flexibility to define the order of authentication methods to be used.

Enable periodic re-authentication of the client.

Enable manual control of the authorization state of the port.

authentication timer dot1x timeout authentication violation

{protect | restrict | shutdown}

dot1x violation-mode

{shutdown | restrict |

protect}

Set the 802.1x timers.

Configure the violation modes that occur when a new device connects to a port or when a new device connects to a port after the maximum number of devices are connected to that port.

Ports in Authorized and Unauthorized States

During 802.1x authentication, depending on the switch port state, the switch can grant a client access to the network. The port starts in the unauthorized state. While in this state, the port that is not configured as a voice

VLAN port disallows all ingress and egress traffic except for 802.1x authentication, CDP, and STP packets.

When a client is successfully authenticated, the port changes to the authorized state, allowing all traffic for the client to flow normally. If the port is configured as a voice VLAN port, the port allows VoIP traffic and

802.1x protocol packets before the client is successfully authenticated.

Note

CDP bypass is not supported and may cause a port to go into err-disabled state.

If a client that does not support 802.1x authentication connects to an unauthorized 802.1x port, the switch requests the client’s identity. In this situation, the client does not respond to the request, the port remains in the unauthorized state, and the client is not granted access to the network.

In contrast, when an 802.1x-enabled client connects to a port that is not running the 802.1x standard, the client initiates the authentication process by sending the EAPOL-start frame. When no response is received, the

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9


Port-Based Authentication and Switch Stacks

client sends the request for a fixed number of times. Because no response is received, the client begins sending frames as if the port is in the authorized state.

You control the port authorization state by using the authentication port-control interface configuration command and these keywords:

• force-authorized—disables 802.1x authentication and causes the port to change to the authorized state without any authentication exchange required. The port sends and receives normal traffic without

802.1x-based authentication of the client. This is the default setting.

• force-unauthorized—causes the port to remain in the unauthorized state, ignoring all attempts by the client to authenticate. The switch cannot provide authentication services to the client through the port.

• auto—enables 802.1x authentication and causes the port to begin in the unauthorized state, allowing only EAPOL frames to be sent and received through the port. The authentication process begins when the link state of the port changes from down to up or when an EAPOL-start frame is received. The switch requests the identity of the client and begins relaying authentication messages between the client and the authentication server. Each client attempting to access the network is uniquely identified by the switch by using the client MAC address.

If the client is successfully authenticated (receives an Accept frame from the authentication server), the port state changes to authorized, and all frames from the authenticated client are allowed through the port. If the authentication fails, the port remains in the unauthorized state, but authentication can be retried. If the authentication server cannot be reached, the switch can resend the request. If no response is received from the server after the specified number of attempts, authentication fails, and network access is not granted.

When a client logs off, it sends an EAPOL-logoff message, causing the switch port to change to the unauthorized state.

If the link state of a port changes from up to down, or if an EAPOL-logoff frame is received, the port returns to the unauthorized state.

Port-Based Authentication and Switch Stacks

If a switch is added to or removed from a switch stack, 802.1x authentication is not affected as long as the IP connectivity between the RADIUS server and the stack remains intact. This statement also applies if the stack master is removed from the switch stack. Note that if the stack master fails, a stack member becomes the new stack master by using the election process, and the 802.1x authentication process continues as usual.

If IP connectivity to the RADIUS server is interrupted because the switch that was connected to the server is removed or fails, these events occur:

• Ports that are already authenticated and that do not have periodic re-authentication enabled remain in the authenticated state. Communication with the RADIUS server is not required.

• Ports that are already authenticated and that have periodic re-authentication enabled (with the dot1x

re-authentication global configuration command) fail the authentication process when the re-authentication occurs. Ports return to the unauthenticated state during the re-authentication process.

Communication with the RADIUS server is required.

For an ongoing authentication, the authentication fails immediately because there is no server connectivity.

If the switch that failed comes up and rejoins the switch stack, the authentications might or might not fail depending on the boot-up time and whether the connectivity to the RADIUS server is re-established by the time the authentication is attempted.

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802.1x Host Mode

To avoid loss of connectivity to the RADIUS server, you should ensure that there is a redundant connection to it. For example, you can have a redundant connection to the stack master and another to a stack member, and if the stack master fails, the switch stack still has connectivity to the RADIUS server.

802.1x Host Mode

You can configure an 802.1x port for single-host or for multiple-hosts mode. In single-host mode, only one client can be connected to the 802.1x-enabled switch port. The switch detects the client by sending an EAPOL frame when the port link state changes to the up state. If a client leaves or is replaced with another client, the switch changes the port link state to down, and the port returns to the unauthorized state.

In multiple-hosts mode, you can attach multiple hosts to a single 802.1x-enabled port. In this mode, only one of the attached clients must be authorized for all clients to be granted network access. If the port becomes unauthorized (re-authentication fails or an EAPOL-logoff message is received), the switch denies network access to all of the attached clients.

In this topology, the wireless access point is responsible for authenticating the clients attached to it, and it also acts as a client to the switch.

Figure 4: Multiple Host Mode Example

Note

For all host modes, the line protocol stays up before authorization when port-based authentication is configured.

The switch supports multidomain authentication (MDA), which allows both a data device and a voice device, such as an IP Phone (Cisco or non-Cisco), to connect to the same switch port.

802.1x Multiple Authentication Mode

Multiple-authentication (multiauth) mode allows multiple authenticated clients on the data VLAN. Each host is individually authenticated. If a voice VLAN is configured, this mode also allows one client on the VLAN.

(If the port detects any additional voice clients, they are discarded from the port, but no violation errors occur.)

If a hub or access point is connected to an 802.1x-enabled port, each connected client must be authenticated.

For non-802.1x devices, you can use MAC authentication bypass or web authentication as the per-host authentication fallback method to authenticate different hosts with different methods on a single port.

There is no limit to the number of data hosts can authenticate on a multiauthport. However, only one voice device is allowed if the voice VLAN is configured. Since there is no host limit defined violation will not be trigger, if a second voice is seen we silently discard it but do not trigger violation. For MDA functionality on the voice VLAN, multiple-authentication mode assigns authenticated devices to either a data or a voice VLAN, depending on the VSAs received from the authentication server.

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Note

When a port is in multiple-authentication mode, the guest VLAN and the authentication-failed VLAN features do not activate.

You can assign a RADIUS-server-supplied VLAN in multi-auth mode, under the following conditions:

• The host is the first host authorized on the port, and the RADIUS server supplies VLAN information

• Subsequent hosts are authorized with a VLAN that matches the operational VLAN.

• A host is authorized on the port with no VLAN assignment, and subsequent hosts either have no VLAN assignment, or their VLAN information matches the operational VLAN.

• The first host authorized on the port has a group VLAN assignment, and subsequent hosts either have no VLAN assignment, or their group VLAN matches the group VLAN on the port. Subsequent hosts must use the same VLAN from the VLAN group as the first host. If a VLAN list is used, all hosts are subject to the conditions specified in the VLAN list.

• Only one voice VLAN assignment is supported on a multi-auth port.

• After a VLAN is assigned to a host on the port, subsequent hosts must have matching VLAN information or be denied access to the port.

• You cannot configure a guest VLAN or an auth-fail VLAN in multi-auth mode.

• The behavior of the critical-auth VLAN is not changed for multi-auth mode. When a host tries to authenticate and the server is not reachable, all authorized hosts are reinitialized in the configured VLAN.

Multi-auth Per User VLAN assignment

The Multi-auth Per User VLAN assignment feature allows you to create multiple operational access VLANs based on VLANs assigned to the clients on the port that has a single configured access VLAN. The port configured as an access port where the traffic for all the VLANs associated with data domain is not dot1q tagged, and these VLANs are treated as native VLANs.

The number of hosts per multi-auth port is 8, however there can be more hosts.

Note

The Multi-auth Per User VLAN assignment feature is not supported for Voice domain. All clients in Voice domain on a port must use the same VLAN.

The following scenarios are associated with the multi-auth Per User VLAN assignments:

Scenario one

When a hub is connected to an access port, and the port is configured with an access VLAN (V0).

The host (H1) is assigned to VLAN (V1) through the hub. The operational VLAN of the port is changed to

V1. This behaviour is similar on a single-host or multi-domain-auth port.

When a second host (H2) is connected and gets assigned to VLAN ( V2), the port will have two operational

VLANs (V1 and V2). If H1 and H2 sends untagged ingress traffic, H1 traffic is mapped to VLAN (V1) and

H2 traffic to VLAN (V2), all egress traffic going out of the port on VLAN (V1) and VLAN (V2) are untagged.

If both the hosts, H1 and H2 are logged out or the sessions are removed due to some reason then VLAN (V1) and VLAN (V2) are removed from the port, and the configured VLAN (V0) is restored on the port.

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Scenario two

When a hub is connected to an access port, and the port is configured with an access VLAN (V0). The host

(H1) is assigned to VLAN (V1) through the hub. The operational VLAN of the port is changed to V1.

When a second host (H2) is connected and gets authorized without explicit vlan policy, H2 is expected to use the configured VLAN (V0) that is restored on the port. A ll egress traffic going out of two operational VLANs,

VLAN (V0) and VLAN (V1) are untagged.

If host (H2 ) is logged out or the session is removed due to some reason then the configured VLAN (V0) is removed from the port, and VLAN (V1) becomes the only operational VLAN on the port.

Scenario three

When a hub is connected to an access port in open mode, and the port is configured with an access VLAN

(V0) .

The host (H1) is assigned to VLAN (V1) through the hub. The operational VLAN of the port is changed to

V1. When a second host (H2) is connected and remains unauthorized, it still has access to operational VLAN

(V1) due to open mode.

If host H1 is logged out or the session is removed due to some reason, VLAN (V1) is removed from the port and host (H2) gets assigned to VLAN (V0).

Note

The combination of Open mode and VLAN assignment has an adverse affect on host (H2) because it has an IP address in the subnet that corresponds to VLAN (V1).

Limitation in Multi-auth Per User VLAN assignment

In the Multi-auth Per User VLAN assignment feature, egress traffic from multiple vlans are untagged on a port where the hosts receive traffic that is not meant for them. This can be a problem with broadcast and multicast traffic.

• IPv4 ARPs: Hosts receive ARP packets from other subnets. This is a problem if two subnets in different

Virtual Routing and Forwarding (VRF) tables with overlapping IP address range are active on the port.

The host ARP cache may get invalid entries.

• IPv6 control packets: In IPv6 deployments, Router Advertisements (RA) are processed by hosts that are not supposed to receive them. When a host from one VLAN receives RA from a different VLAN, the host assign incorrect IPv6 address to itself. Such a host is unable to get access to the network.

The workaround is to enable the IPv6 first hop security so that the broadcast ICMPv6 packets are converted to unicast and sent out from multi-auth enabled ports.. The packet is replicated for each client in multi-auth port belonging to the VLAN and the destination MAC is set to an individual client. Ports having one VLAN, ICMPv6 packets broadcast normally.

• IP multicast: Multicast traffic destined to a multicast group gets replicated for different VLANs if the hosts on those VLANs join the multicast group. When two hosts in different VLANs join a multicast group (on the same mutli-auth port), two copies of each multicast packet are sent out from that port.

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MAC Move

MAC Move

When a MAC address is authenticated on one switch port, that address is not allowed on another authentication manager-enabled port of the switch. If the switch detects that same MAC address on another authentication manager-enabled port, the address is not allowed.

There are situations where a MAC address might need to move from one port to another on the same switch.

For example, when there is another device (for example a hub or an IP phone) between an authenticated host and a switch port, you might want to disconnect the host from the device and connect it directly to another port on the same switch.

You can globally enable MAC move so the device is reauthenticated on the new port. When a host moves to a second port, the session on the first port is deleted, and the host is reauthenticated on the new port. MAC move is supported on all host modes. (The authenticated host can move to any port on the switch, no matter which host mode is enabled on the that port.) When a MAC address moves from one port to another, the switch terminates the authenticated session on the original port and initiates a new authentication sequence on the new port. The MAC move feature applies to both voice and data hosts.

Note

In open authentication mode, a MAC address is immediately moved from the original port to the new port, with no requirement for authorization on the new port.

MAC Replace

The MAC replace feature can be configured to address the violation that occurs when a host attempts to connect to a port where another host was previously authenticated.

Note

This feature does not apply to ports in multi-auth mode, because violations are not triggered in that mode.

It does not apply to ports in multiple host mode, because in that mode, only the first host requires authentication.

If you configure the authentication violation interface configuration command with the replace keyword, the authentication process on a port in multi-domain mode is:

• A new MAC address is received on a port with an existing authenticated MAC address.

• The authentication manager replaces the MAC address of the current data host on the port with the new

MAC address.

• The authentication manager initiates the authentication process for the new MAC address.

• If the authentication manager determines that the new host is a voice host, the original voice host is removed.

If a port is in open authentication mode, any new MAC address is immediately added to the MAC address table.

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802.1x Accounting

802.1x Accounting

The 802.1x standard defines how users are authorized and authenticated for network access but does not keep track of network usage. 802.1x accounting is disabled by default. You can enable 802.1x accounting to monitor this activity on 802.1x-enabled ports:

• User successfully authenticates.

• User logs off.

• Link-down occurs.

• Re-authentication successfully occurs.

• Re-authentication fails.

The switch does not log 802.1x accounting information. Instead, it sends this information to the RADIUS server, which must be configured to log accounting messages.

802.1x Accounting Attribute-Value Pairs

The information sent to the RADIUS server is represented in the form of Attribute-Value (AV) pairs. These

AV pairs provide data for different applications. (For example, a billing application might require information that is in the Acct-Input-Octets or the Acct-Output-Octets attributes of a RADIUS packet.)

AV pairs are automatically sent by a switch that is configured for 802.1x accounting. Three types of RADIUS accounting packets are sent by a switch:

• START–sent when a new user session starts

• INTERIM–sent during an existing session for updates

• STOP–sent when a session terminates

You can view the AV pairs that are being sent by the switch by entering the debug radius accounting privileged EXEC command. For more information about this command, see the Cisco IOS Debug Command

Reference, Release 12.4.

This table lists the AV pairs and when they are sent are sent by the switch.

Table 3: Accounting AV Pairs

Attribute Number AV Pair Name

Attribute[1] User-Name

Attribute[4]

Attribute[5]

NAS-IP-Address

NAS-Port

Attribute[8]

Attribute[25]

Framed-IP-Address

Class

START

Always

INTERIM

Always

Always Always

Always

Never

Always

Sometimes

3

Always Always

STOP

Always

Always

Always

Sometimes

Always

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802.1x Readiness Check

Attribute Number AV Pair Name

Attribute[30] Called-Station-ID

Attribute[31] Calling-Station-ID

Attribute[40]

Attribute[41]

Attribute[42]

Attribute[43]

Attribute[47]

Attribute[48]

Attribute[44]

Attribute[45]

Attribute[46]

Attribute[49]

Attribute[61]

Acct-Status-Type

Acct-Delay-Time

Acct-Input-Octets

Acct-Output-Octets

Acct-Input-Packets

Acct-Output-Packets

Acct-Session-ID

START

Always

Always

INTERIM

Always

Always

Always Always

Always Always

Never Always

Never

Never

Always

Always

Never Always

Always Always

Acct-Authentic

Acct-Session-Time

Always

Never

Acct-Terminate-Cause Never

Always

Always

Never

NAS-Port-Type Always Always

STOP

Always

Always

Always

Always

Always

Always

Always

Always

Always

Always

Always

Always

Always

3 The Framed-IP-Address AV pair is sent when a valid static IP address is configured or w when a Dynamic Host Control Protocol (DHCP) binding exists for the host in the DHCP snooping bindings table.

802.1x Readiness Check

The 802.1x readiness check monitors 802.1x activity on all the switch ports and displays information about the devices connected to the ports that support 802.1x. You can use this feature to determine if the devices connected to the switch ports are 802.1x-capable. You use an alternate authentication such as MAC authentication bypass or web authentication for the devices that do not support 802.1x functionality.

This feature only works if the supplicant on the client supports a query with the NOTIFY EAP notification packet. The client must respond within the 802.1x timeout value.

Related Topics

Configuring 802.1x Readiness Check, on page 39

Switch-to-RADIUS-Server Communication

RADIUS security servers are identified by their hostname or IP address, hostname and specific UDP port numbers, or IP address and specific UDP port numbers. The combination of the IP address and UDP port

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802.1x Authentication with VLAN Assignment

number creates a unique identifier, which enables RADIUS requests to be sent to multiple UDP ports on a server at the same IP address. If two different host entries on the same RADIUS server are configured for the same service—for example, authentication—the second host entry configured acts as the fail-over backup to the first one. The RADIUS host entries are tried in the order that they were configured.

Related Topics

Configuring the Switch-to-RADIUS-Server Communication, on page 48

802.1x Authentication with VLAN Assignment

The switch supports 802.1x authentication with VLAN assignment. After successful 802.1x authentication of a port, the RADIUS server sends the VLAN assignment to configure the switch port. The RADIUS server database maintains the username-to-VLAN mappings, assigning the VLAN based on the username of the client connected to the switch port. You can use this feature to limit network access for certain users.

Voice device authentication is supported with multidomain host mode in Cisco IOS Release 12.2(37)SE. In

Cisco IOS Release 12.2(40)SE and later, when a voice device is authorized and the RADIUS server returned an authorized VLAN, the voice VLAN on the port is configured to send and receive packets on the assigned voice VLAN. Voice VLAN assignment behaves the same as data VLAN assignment on multidomain authentication (MDA)-enabled ports.

When configured on the switch and the RADIUS server, 802.1x authentication with VLAN assignment has these characteristics:

• If no VLAN is supplied by the RADIUS server or if 802.1x authentication is disabled, the port is configured in its access VLAN after successful authentication. Recall that an access VLAN is a VLAN assigned to an access port. All packets sent from or received on this port belong to this VLAN.

• If 802.1x authentication is enabled but the VLAN information from the RADIUS server is not valid, authorization fails and configured VLAN remains in use. This prevents ports from appearing unexpectedly in an inappropriate VLAN because of a configuration error.

Configuration errors could include specifying a VLAN for a routed port, a malformed VLAN ID, a nonexistent or internal (routed port) VLAN ID, an RSPAN VLAN, a shut down or suspended VLAN.

In the case of a multidomain host port, configuration errors can also be due to an attempted assignment of a data VLAN that matches the configured or assigned voice VLAN ID (or the reverse).

• If 802.1x authentication is enabled and all information from the RADIUS server is valid, the authorized device is placed in the specified VLAN after authentication.

• If the multiple-hosts mode is enabled on an 802.1x port, all hosts are placed in the same VLAN (specified by the RADIUS server) as the first authenticated host.

• Enabling port security does not impact the RADIUS server-assigned VLAN behavior.

• If 802.1x authentication is disabled on the port, it is returned to the configured access VLAN and configured voice VLAN.

• If an 802.1x port is authenticated and put in the RADIUS server-assigned VLAN, any change to the port access VLAN configuration does not take effect. In the case of a multidomain host, the same applies to voice devices when the port is fully authorized with these exceptions:

◦If the VLAN configuration change of one device results in matching the other device configured or assigned VLAN, then authorization of all devices on the port is terminated and multidomain

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802.1x Authentication with Per-User ACLs

host mode is disabled until a valid configuration is restored where data and voice device configured

VLANs no longer match.

◦If a voice device is authorized and is using a downloaded voice VLAN, the removal of the voice

VLAN configuration, or modifying the configuration value to dot1p or untagged results in voice device un-authorization and the disablement of multi-domain host mode.

When the port is in the force authorized, force unauthorized, unauthorized, or shutdown state, it is put into the configured access VLAN.

If an 802.1x port is authenticated and put in the RADIUS server-assigned VLAN, any change to the port access VLAN configuration does not take effect. In the case of a multidomain host, the same applies to voice devices when the port is fully authorized with these exceptions:

• If the VLAN configuration change of one device results in matching the other device configured or assigned VLAN, authorization of all devices on the port is terminated and multidomain host mode is disabled until a valid configuration is restored where data and voice device configured VLANs no longer match.

• If a voice device is authorized and is using a downloaded voice VLAN, the removal of the voice VLAN configuration, or modifying the configuration value to dot1p or untagged results in voice device un-authorization and the disablement of multi-domain host mode.

When the port is in the force authorized, force unauthorized, unauthorized, or shutdown state, it is put into the configured access VLAN.

The 802.1x authentication with VLAN assignment feature is not supported on trunk ports, dynamic ports, or with dynamic-access port assignment through a VLAN Membership Policy Server (VMPS).

To configure VLAN assignment you need to perform these tasks:

• Enable AAA authorization by using the network keyword to allow interface configuration from the

RADIUS server.

• Enable 802.1x authentication. (The VLAN assignment feature is automatically enabled when you configure 802.1x authentication on an access port).

• Assign vendor-specific tunnel attributes in the RADIUS server. The RADIUS server must return these attributes to the switch:

◦[64] Tunnel-Type = VLAN

◦[65] Tunnel-Medium-Type = 802

◦[81] Tunnel-Private-Group-ID = VLAN name or VLAN ID

◦[83] Tunnel-Preference

Attribute [64] must contain the value VLAN (type 13). Attribute [65] must contain the value 802 (type

6). Attribute [81] specifies the VLAN name or VLAN ID assigned to the IEEE 802.1x-authenticated user.

802.1x Authentication with Per-User ACLs

You can enable per-user access control lists (ACLs) to provide different levels of network access and service to an 802.1x-authenticated user. When the RADIUS server authenticates a user connected to an 802.1x port,

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802.1x Authentication with Downloadable ACLs and Redirect URLs

it retrieves the ACL attributes based on the user identity and sends them to the switch. The switch applies the attributes to the 802.1x port for the duration of the user session. The switch removes the per-user ACL configuration when the session is over, if authentication fails, or if a link-down condition occurs. The switch does not save RADIUS-specified ACLs in the running configuration. When the port is unauthorized, the switch removes the ACL from the port.

You can configure router ACLs and input port ACLs on the same switch. However, a port ACL takes precedence over a router ACL. If you apply input port ACL to an interface that belongs to a VLAN, the port ACL takes precedence over an input router ACL applied to the VLAN interface. Incoming packets received on the port to which a port ACL is applied are filtered by the port ACL. Incoming routed packets received on other ports are filtered by the router ACL. Outgoing routed packets are filtered by the router ACL. To avoid configuration conflicts, you should carefully plan the user profiles stored on the RADIUS server.

RADIUS supports per-user attributes, including vendor-specific attributes. These vendor-specific attributes

(VSAs) are in octet-string format and are passed to the switch during the authentication process. The VSAs used for per-user ACLs are inacl#<n> for the ingress direction and outacl#<n> for the egress direction. MAC

ACLs are supported only in the ingress direction. The switch supports VSAs only in the ingress direction. It does not support port ACLs in the egress direction on Layer 2 ports.

Use only the extended ACL syntax style to define the per-user configuration stored on the RADIUS server.

When the definitions are passed from the RADIUS server, they are created by using the extended naming convention. However, if you use the Filter-Id attribute, it can point to a standard ACL.

You can use the Filter-Id attribute to specify an inbound or outbound ACL that is already configured on the switch. The attribute contains the ACL number followed by .in for ingress filtering or .out for egress filtering.

If the RADIUS server does not allow the .in or .out syntax, the access list is applied to the outbound ACL by default. Because of limited support of Cisco IOS access lists on the switch, the Filter-Id attribute is supported only for IP ACLs numbered 1 to 199 and 1300 to 2699 (IP standard and IP extended ACLs).

The maximum size of the per-user ACL is 4000 ASCII characters but is limited by the maximum size of

RADIUS-server per-user ACLs.

To configure per-user ACLs:

• Enable AAA authentication.

• Enable AAA authorization by using the network keyword to allow interface configuration from the

RADIUS server.

• Enable 802.1x authentication.

• Configure the user profile and VSAs on the RADIUS server.

• Configure the 802.1x port for single-host mode.

Note

Per-user ACLs are supported only in single-host mode.


You can download ACLs and redirect URLs from a RADIUS server to the switch during 802.1x authentication or MAC authentication bypass of the host. You can also download ACLs during web authentication.

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Note

A downloadable ACL is also referred to as a dACL.

If more than one host is authenticated and the host is in single-host, MDA, or multiple-authentication mode, the switch changes the source address of the ACL to the host IP address.

You can apply the ACLs and redirect URLs to all the devices connected to the 802.1x-enabled port.

If no ACLs are downloaded during 802.1x authentication, the switch applies the static default ACL on the port to the host. On a voice VLAN port configured in multi-auth or MDA mode, the switch applies the ACL only to the phone as part of the authorization policies.

Beginning with Cisco IOS Release 12.2(55)SE, if there is no static ACL on a port, a dynamic auth-default

ACL is created, and policies are enforced before dACLs are downloaded and applied.

Note

The auth-default-ACL does not appear in the running configuration.

The auth-default ACL is created when at least one host with an authorization policy is detected on the port.

The auth-default ACL is removed from the port when the last authenticated session ends. You can configure the auth-default ACL by using the ip access-list extended auth-default-acl global configuration command.

Note

The auth-default-ACL does not support Cisco Discovery Protocol (CDP) bypass in the single host mode.

You must configure a static ACL on the interface to support CDP bypass.

The 802.1x and MAB authentication methods support two authentication modes, open and closed. If there is no static ACL on a port in closed authentication mode:

• An auth-default-ACL is created.

• The auth-default-ACL allows only DHCP traffic until policies are enforced.

• When the first host authenticates, the authorization policy is applied without IP address insertion.

• When a second host is detected, the policies for the first host are refreshed, and policies for the first and subsequent sessions are enforced with IP address insertion.

If there is no static ACL on a port in open authentication mode:

• An auth-default-ACL-OPEN is created and allows all traffic.

• Policies are enforced with IP address insertion to prevent security breaches.

• Web authentication is subject to the auth-default-ACL-OPEN.

To control access for hosts with no authorization policy, you can configure a directive. The supported values for the directive are open and default. When you configure the open directive, all traffic is allowed. The default directive subjects traffic to the access provided by the port. You can configure the directive either in the user profile on the AAA server or on the switch. To configure the directive on the AAA server, use the

authz-directive =<open/default> global command. To configure the directive on the switch, use the epm

access-control open global configuration command.

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Note

The default value of the directive is default.

If a host falls back to web authentication on a port without a configured ACL:

• If the port is in open authentication mode, the auth-default-ACL-OPEN is created.

• If the port is in closed authentication mode, the auth-default-ACL is created.

The access control entries (ACEs) in the fallback ACL are converted to per-user entries. If the configured fallback profile does not include a fallback ACL, the host is subject to the auth-default-ACL associated with the port.

Note

If you use a custom logo with web authentication and it is stored on an external server, the port ACL must allow access to the external server before authentication. You must either configure a static port ACL or change the auth-default-ACL to provide appropriate access to the external server.

Cisco Secure ACS and Attribute-Value Pairs for the Redirect URL

The switch uses these cisco-av-pair VSAs:

• url-redirect is the HTTP or HTTPS URL.

• url-redirect-acl is the switch ACL name or number.

The switch uses the CiscoSecure-defined-ACL attribute value pair to intercept an HTTP or HTTPS request from the end point. The switch then forwards the client web browser to the specified redirect address. The url-redirect AV pair on the Cisco Secure ACS contains the URL to which the web browser is redirected. The url-redirect-acl attribute value pair contains the name or number of an ACL that specifies the HTTP or HTTPS traffic to redirect.

Note

• Traffic that matches a permit ACE in the ACL is redirected.

• Define the URL redirect ACL and the default port ACL on the switch.

If a redirect URL is configured for a client on the authentication server, a default port ACL on the connected client switch port must also be configured.

Cisco Secure ACS and Attribute-Value Pairs for Downloadable ACLs

You can set the CiscoSecure-Defined-ACL Attribute-Value (AV) pair on the Cisco Secure ACS with the

RADIUS cisco-av-pair vendor-specific attributes (VSAs). This pair specifies the names of the downloadable

ACLs on the Cisco Secure ACS with the #ACL#-IP-name-number attribute.

• The name is the ACL name.

• The number is the version number (for example, 3f783768).

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VLAN ID-based MAC Authentication

If a downloadable ACL is configured for a client on the authentication server, a default port ACL on the connected client switch port must also be configured.

If the default ACL is configured on the switch and the Cisco Secure ACS sends a host-access-policy to the switch, it applies the policy to traffic from the host connected to a switch port. If the policy does not apply, the switch applies the default ACL. If the Cisco Secure ACS sends the switch a downloadable ACL, this ACL takes precedence over the default ACL that is configured on the switch port. However, if the switch receives an host access policy from the Cisco Secure ACS but the default ACL is not configured, the authorization failure is declared.

VLAN ID-based MAC Authentication

You can use VLAN ID-based MAC authentication if you wish to authenticate hosts based on a static VLAN

ID instead of a downloadable VLAN. When you have a static VLAN policy configured on your switch, VLAN information is sent to an IAS (Microsoft) RADIUS server along with the MAC address of each host for authentication. The VLAN ID configured on the connected port is used for MAC authentication. By using

VLAN ID-based MAC authentication with an IAS server, you can have a fixed number of VLANs in the network.

The feature also limits the number of VLANs monitored and handled by STP. The network can be managed as a fixed VLAN.

Note

This feature is not supported on Cisco ACS Server. (The ACS server ignores the sent VLAN-IDs for new hosts and only authenticates based on the MAC address.)

802.1x Authentication with Guest VLAN

You can configure a guest VLAN for each 802.1x port on the switch to provide limited services to clients, such as downloading the 802.1x client. These clients might be upgrading their system for 802.1x authentication, and some hosts, such as Windows 98 systems, might not be IEEE 802.1x-capable.

When you enable a guest VLAN on an 802.1x port, the switch assigns clients to a guest VLAN when the switch does not receive a response to its EAP request/identity frame or when EAPOL packets are not sent by the client.

The switch maintains the EAPOL packet history. If an EAPOL packet is detected on the interface during the lifetime of the link, the switch determines that the device connected to that interface is an IEEE 802.1x-capable supplicant, and the interface does not change to the guest VLAN state. EAPOL history is cleared if the interface link status goes down. If no EAPOL packet is detected on the interface, the interface changes to the guest

VLAN state.

If the switch is trying to authorize an 802.1x-capable voice device and the AAA server is unavailable, the authorization attempt fails, but the detection of the EAPOL packet is saved in the EAPOL history. When the

AAA server becomes available, the switch authorizes the voice device. However, the switch no longer allows other devices access to the guest VLAN. To prevent this situation, use one of these command sequences:

• Enter the authentication event no-response action authorize vlan vlan-id interface configuration command to allow access to the guest VLAN.

• Enter the shutdown interface configuration command followed by the no shutdown interface configuration command to restart the port.

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802.1x Authentication with Restricted VLAN

If devices send EAPOL packets to the switch during the lifetime of the link, the switch no longer allows clients that fail authentication access to the guest VLAN.

Note

If an EAPOL packet is detected after the interface has changed to the guest VLAN, the interface reverts to an unauthorized state, and 802.1x authentication restarts.

Any number of 802.1x-incapable clients are allowed access when the switch port is moved to the guest VLAN.

If an 802.1x-capable client joins the same port on which the guest VLAN is configured, the port is put into the unauthorized state in the user-configured access VLAN, and authentication is restarted.

Guest VLANs are supported on 802.1x ports in single host, multiple host, multi-auth and multi-domain modes.

You can configure any active VLAN except an RSPAN VLAN, a private VLAN, or a voice VLAN as an

802.1x guest VLAN. The guest VLAN feature is not supported on internal VLANs (routed ports) or trunk ports; it is supported only on access ports.

The switch supports MAC authentication bypass. When MAC authentication bypass is enabled on an 802.1x

port, the switch can authorize clients based on the client MAC address when IEEE 802.1x authentication times out while waiting for an EAPOL message exchange. After detecting a client on an 802.1x port, the switch waits for an Ethernet packet from the client. The switch sends the authentication server a

RADIUS-access/request frame with a username and password based on the MAC address. If authorization succeeds, the switch grants the client access to the network. If authorization fails, the switch assigns the port to the guest VLAN if one is specified.

802.1x Authentication with Restricted VLAN

You can configure a restricted VLAN (also referred to as an authentication failed VLAN) for each IEEE 802.1x

port on a switch stack or a switch to provide limited services to clients that cannot access the guest VLAN.

These clients are 802.1x-compliant and cannot access another VLAN because they fail the authentication process. A restricted VLAN allows users without valid credentials in an authentication server (typically, visitors to an enterprise) to access a limited set of services. The administrator can control the services available to the restricted VLAN.

Note

You can configure a VLAN to be both the guest VLAN and the restricted VLAN if you want to provide the same services to both types of users.

Without this feature, the client attempts and fails authentication indefinitely, and the switch port remains in the spanning-tree blocking state. With this feature, you can configure the switch port to be in the restricted

VLAN after a specified number of authentication attempts (the default value is 3 attempts).

The authenticator counts the failed authentication attempts for the client. When this count exceeds the configured maximum number of authentication attempts, the port moves to the restricted VLAN. The failed attempt count increments when the RADIUS server replies with either an EAP failure or an empty response without an EAP packet. When the port moves into the restricted VLAN, the failed attempt counter resets.

Users who fail authentication remain in the restricted VLAN until the next re-authentication attempt. A port in the restricted VLAN tries to re-authenticate at configured intervals (the default is 60 seconds). If re-authentication fails, the port remains in the restricted VLAN. If re-authentication is successful, the port moves either to the configured VLAN or to a VLAN sent by the RADIUS server. You can disable re-authentication. If you do this, the only way to restart the authentication process is for the port to receive a

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802.1x Authentication with Inaccessible Authentication Bypass

link down or EAP logoff event. We recommend that you keep re-authentication enabled if a client might connect through a hub. When a client disconnects from the hub, the port might not receive the link down or

EAP logoff event.

After a port moves to the restricted VLAN, a simulated EAP success message is sent to the client. This prevents clients from indefinitely attempting authentication. Some clients (for example, devices running Windows XP) cannot implement DHCP without EAP success.

Restricted VLANs are supported on 802.1x ports in all host modes and on Layer 2 ports.

You can configure any active VLAN except an RSPAN VLAN, a primary private VLAN, or a voice VLAN as an 802.1x restricted VLAN. The restricted VLAN feature is not supported on internal VLANs (routed ports) or trunk ports; it is supported only on access ports.

Other security port features such as dynamic ARP Inspection, DHCP snooping, and IP source guard can be configured independently on a restricted VLAN.


Use the inaccessible authentication bypass feature, also referred to as critical authentication or the AAA fail

policy, when the switch cannot reach the configured RADIUS servers and new hosts cannot be authenticated.

You can configure the switch to connect those hosts to critical ports.

When a new host tries to connect to the critical port, that host is moved to a user-specified access VLAN, the

critical VLAN. The administrator gives limited authentication to the hosts.

When the switch tries to authenticate a host connected to a critical port, the switch checks the status of the configured RADIUS server. If a server is available, the switch can authenticate the host. However, if all the

RADIUS servers are unavailable, the switch grants network access to the host and puts the port in the

critical-authentication state, which is a special case of the authentication state.

Note

If critical authentication is configured on interface, then vlan used for critical authorization (critical vlan) should be active on the switch. If the critical vlan is inactive (or) down, critical authentication session will keep trying to enable inactive vlan and fail repeatedly. This can lead to large amount of memory holding.

Inaccessible Authentication Bypass Support on Multiple-Authentication Ports

When a port is configured on any host mode and the AAA server is unavailable, the port is then configured to multi-host mode and moved to the critical VLAN. To support this inaccessible bypass on multiple-authentication (multiauth) ports, use the authentication event server dead action reinitialize vlan

vlan-id command. When a new host tries to connect to the critical port, that port is reinitialized and all the connected hosts are moved to the user-specified access VLAN.

This command is supported on all host modes.

Inaccessible Authentication Bypass Authentication Results

The behavior of the inaccessible authentication bypass feature depends on the authorization state of the port:

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• If the port is unauthorized when a host connected to a critical port tries to authenticate and all servers are unavailable, the switch puts the port in the critical-authentication state in the RADIUS-configured or user-specified access VLAN.

• If the port is already authorized and reauthentication occurs, the switch puts the critical port in the critical-authentication state in the current VLAN, which might be the one previously assigned by the

RADIUS server.

• If the RADIUS server becomes unavailable during an authentication exchange, the current exchange times out, and the switch puts the critical port in the critical-authentication state during the next authentication attempt.

You can configure the critical port to reinitialize hosts and move them out of the critical VLAN when the

RADIUS server is again available. When this is configured, all critical ports in the critical-authentication state are automatically re-authenticated.

Inaccessible Authentication Bypass Feature Interactions

Inaccessible authentication bypass interacts with these features:

• Guest VLAN—Inaccessible authentication bypass is compatible with guest VLAN. When a guest VLAN is enabled on 8021.x port, the features interact as follows:

◦If at least one RADIUS server is available, the switch assigns a client to a guest VLAN when the switch does not receive a response to its EAP request/identity frame or when EAPOL packets are not sent by the client.

◦If all the RADIUS servers are not available and the client is connected to a critical port, the switch authenticates the client and puts the critical port in the critical-authentication state in the

RADIUS-configured or user-specified access VLAN.

◦If all the RADIUS servers are not available and the client is not connected to a critical port, the switch might not assign clients to the guest VLAN if one is configured.

◦If all the RADIUS servers are not available and if a client is connected to a critical port and was previously assigned to a guest VLAN, the switch keeps the port in the guest VLAN.

• Restricted VLAN—If the port is already authorized in a restricted VLAN and the RADIUS servers are unavailable, the switch puts the critical port in the critical-authentication state in the restricted VLAN.

• 802.1x accounting—Accounting is not affected if the RADIUS servers are unavailable.

• Private VLAN—You can configure inaccessible authentication bypass on a private VLAN host port.

The access VLAN must be a secondary private VLAN.

• Voice VLAN—Inaccessible authentication bypass is compatible with voice VLAN, but the

RADIUS-configured or user-specified access VLAN and the voice VLAN must be different.

• Remote Switched Port Analyzer (RSPAN)—Do not configure an RSPAN VLAN as the

RADIUS-configured or user-specified access VLAN for inaccessible authentication bypass.

In a switch stack:

• The stack master checks the status of the RADIUS servers by sending keepalive packets. When the status of a RADIUS server changes, the stack master sends the information to the stack members. The stack members can then check the status of RADIUS servers when re-authenticating critical ports.

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802.1x Critical Voice VLAN

• If the new stack master is elected, the link between the switch stack and RADIUS server might change, and the new stack immediately sends keepalive packets to update the status of the RADIUS servers. If the server status changes from dead to alive, the switch re-authenticates all switch ports in the critical-authentication state.

When a member is added to the stack, the stack master sends the member the server status.

Note

Switch stacks are supported only on Catalyst 2960-S switches running the LAN base image.

802.1x Critical Voice VLAN

When an IP phone connected to a port is authenticated by the access control server (ACS), the phone is put into the voice domain. If the ACS is not reachable, the switch cannot determine if the device is a voice device.

If the server is unavailable, the phone cannot access the voice network and therefore cannot operate.

For data traffic, you can configure inaccessible authentication bypass, or critical authentication, to allow traffic to pass through on the native VLAN when the server is not available. If the RADIUS authentication server is unavailable (down) and inaccessible authentication bypass is enabled, the switch grants the client access to the network and puts the port in the critical-authentication state in the RADIUS-configured or the user-specified access VLAN. When the switch cannot reach the configured RADIUS servers and new hosts cannot be authenticated, the switch connects those hosts to critical ports. A new host trying to connect to the critical port is moved to a user-specified access VLAN, the critical VLAN, and granted limited authentication.

You can enter the authentication event server dead action authorize voice interface configuration command to configure the critical voice VLAN feature. When the ACS does not respond, the port goes into critical authentication mode. When traffic coming from the host is tagged with the voice VLAN, the connected device

(the phone) is put in the configured voice VLAN for the port. The IP phones learn the voice VLAN identification through CDP (Cisco devices) or through LLDP or DHCP.

You can configure the voice VLAN for a port by entering the switchport voice vlan vlan-id interface configuration command.

This feature is supported in multidomain and multi-auth host modes. Although you can enter the command when the switch in single-host or multi-host mode, the command has no effect unless the device changes to multidomain or multi-auth host mode.

802.1x User Distribution

You can configure 802.1x user distribution to load-balance users with the same group name across multiple different VLANs.

The VLANs are either supplied by the RADIUS server or configured through the switch CLI under a VLAN group name.

• Configure the RADIUS server to send more than one VLAN name for a user. The multiple VLAN names can be sent as part of the response to the user. The 802.1x user distribution tracks all the users in a particular VLAN and achieves load balancing by moving the authorized user to the least populated

VLAN.

• Configure the RADIUS server to send a VLAN group name for a user. The VLAN group name can be sent as part of the response to the user. You can search for the selected VLAN group name among the

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IEEE 802.1x Authentication with Voice VLAN Ports

VLAN group names that you configured by using the switch CLI. If the VLAN group name is found, the corresponding VLANs under this VLAN group name are searched to find the least populated VLAN.

Load balancing is achieved by moving the corresponding authorized user to that VLAN.

Note

The RADIUS server can send the VLAN information in any combination of VLAN-IDs,

VLAN names, or VLAN groups.

802.1x User Distribution Configuration Guidelines

• Confirm that at least one VLAN is mapped to the VLAN group.

• You can map more than one VLAN to a VLAN group.

• You can modify the VLAN group by adding or deleting a VLAN.

• When you clear an existing VLAN from the VLAN group name, none of the authenticated ports in the

VLAN are cleared, but the mappings are removed from the existing VLAN group.

• If you clear the last VLAN from the VLAN group name, the VLAN group is cleared.

• You can clear a VLAN group even when the active VLANs are mapped to the group. When you clear a VLAN group, none of the ports or users that are in the authenticated state in any VLAN within the group are cleared, but the VLAN mappings to the VLAN group are cleared.

IEEE 802.1x Authentication with Voice VLAN Ports

A voice VLAN port is a special access port associated with two VLAN identifiers:

• VVID to carry voice traffic to and from the IP phone. The VVID is used to configure the IP phone connected to the port.

• PVID to carry the data traffic to and from the workstation connected to the switch through the IP phone.

The PVID is the native VLAN of the port.

The IP phone uses the VVID for its voice traffic, regardless of the authorization state of the port. This allows the phone to work independently of IEEE 802.1x authentication.

In single-host mode, only the IP phone is allowed on the voice VLAN. In multiple-hosts mode, additional clients can send traffic on the voice VLAN after a supplicant is authenticated on the PVID. When multiple-hosts mode is enabled, the supplicant authentication affects both the PVID and the VVID.

A voice VLAN port becomes active when there is a link, and the device MAC address appears after the first

CDP message from the IP phone. Cisco IP phones do not relay CDP messages from other devices. As a result, if several IP phones are connected in series, the switch recognizes only the one directly connected to it. When

IEEE 802.1x authentication is enabled on a voice VLAN port, the switch drops packets from unrecognized

IP phones more than one hop away.

When IEEE 802.1x authentication is enabled on a switch port, you can configure an access port VLAN that is also a voice VLAN.

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IEEE 802.1x Authentication with Port Security

When IP phones are connected to an 802.1x-enabled switch port that is in single host mode, the switch grants the phones network access without authenticating them. We recommend that you use multidomain authentication

(MDA) on the port to authenticate both a data device and a voice device, such as an IP phone

Note

If you enable IEEE 802.1x authentication on an access port on which a voice VLAN is configured and to which a Cisco IP Phone is connected, the Cisco IP phone loses connectivity to the switch for up to 30 seconds.

IEEE 802.1x Authentication with Port Security

In general, Cisco does not recommend enabling port security when IEEE 802.1x is enabled. Since IEEE 802.1x

enforces a single MAC address per port (or per VLAN when MDA is configured for IP telephony), port security is redundant and in some cases may interfere with expected IEEE 802.1x operations.

IEEE 802.1x Authentication with Wake-on-LAN

The IEEE 802.1x authentication with wake-on-LAN (WoL) feature allows dormant PCs to be powered when the switch receives a specific Ethernet frame, known as the magic packet. You can use this feature in environments where administrators need to connect to systems that have been powered down.

When a host that uses WoL is attached through an IEEE 802.1x port and the host powers off, the IEEE 802.1x

port becomes unauthorized. The port can only receive and send EAPOL packets, and WoL magic packets cannot reach the host. When the PC is powered off, it is not authorized, and the switch port is not opened.

When the switch uses IEEE 802.1x authentication with WoL, the switch forwards traffic to unauthorized

IEEE 802.1x ports, including magic packets. While the port is unauthorized, the switch continues to block ingress traffic other than EAPOL packets. The host can receive packets but cannot send packets to other devices in the network.

Note

If PortFast is not enabled on the port, the port is forced to the bidirectional state.

When you configure a port as unidirectional by using the authentication control-direction in interface configuration command, the port changes to the spanning-tree forwarding state. The port can send packets to the host but cannot receive packets from the host.

When you configure a port as bidirectional by using the authentication control-direction both interface configuration command, the port is access-controlled in both directions. The port does not receive packets from or send packets to the host.

IEEE 802.1x Authentication with MAC Authentication Bypass

You can configure the switch to authorize clients based on the client MAC address by using the MAC authentication bypass feature. For example, you can enable this feature on IEEE 802.1x ports connected to devices such as printers.

If IEEE 802.1x authentication times out while waiting for an EAPOL response from the client, the switch tries to authorize the client by using MAC authentication bypass.

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IEEE 802.1x Authentication with MAC Authentication Bypass

When the MAC authentication bypass feature is enabled on an IEEE 802.1x port, the switch uses the MAC address as the client identity. The authentication server has a database of client MAC addresses that are allowed network access. After detecting a client on an IEEE 802.1x port, the switch waits for an Ethernet packet from the client. The switch sends the authentication server a RADIUS-access/request frame with a username and password based on the MAC address. If authorization succeeds, the switch grants the client access to the network. If authorization fails, the switch assigns the port to the guest VLAN if one is configured. This process works for most client devices; however, it does not work for clients that use an alternate MAC address format.

You can configure how MAB authentication is performed for clients with MAC addresses that deviate from the standard format or where the RADIUS configuration requires the user name and password to differ.

If an EAPOL packet is detected on the interface during the lifetime of the link, the switch determines that the device connected to that interface is an 802.1x-capable supplicant and uses 802.1x authentication (not MAC authentication bypass) to authorize the interface. EAPOL history is cleared if the interface link status goes down.

If the switch already authorized a port by using MAC authentication bypass and detects an IEEE 802.1x

supplicant, the switch does not unauthorize the client connected to the port. When re-authentication occurs, the switch uses the authentication or re-authentication methods configured on the port, if the previous session ended because the Termination-Action RADIUS attribute value is DEFAULT.

Clients that were authorized with MAC authentication bypass can be re-authenticated. The re-authentication process is the same as that for clients that were authenticated with IEEE 802.1x. During re-authentication, the port remains in the previously assigned VLAN. If re-authentication is successful, the switch keeps the port in the same VLAN. If re-authentication fails, the switch assigns the port to the guest VLAN, if one is configured.

If re-authentication is based on the Session-Timeout RADIUS attribute (Attribute[27]) and the

Termination-Action RADIUS attribute (Attribute [29]) and if the Termination-Action RADIUS attribute

(Attribute [29]) action is Initialize (the attribute value is DEFAULT), the MAC authentication bypass session ends, and connectivity is lost during re-authentication. If MAC authentication bypass is enabled and the IEEE

802.1x authentication times out, the switch uses the MAC authentication bypass feature to initiate re-authorization. For more information about these AV pairs, see RFC 3580, “IEEE 802.1X Remote

Authentication Dial In User Service (RADIUS) Usage Guidelines.”

MAC authentication bypass interacts with the features:

• IEEE 802.1x authentication—You can enable MAC authentication bypass only if 802.1x authentication is enabled on the port .

• Guest VLAN—If a client has an invalid MAC address identity, the switch assigns the client to a guest

VLAN if one is configured.

• Restricted VLAN—This feature is not supported when the client connected to an IEEE 802.lx port is authenticated with MAC authentication bypass.

• Port security

• Voice VLAN

• Private VLAN—You can assign a client to a private VLAN.

• Network Edge Access Topology (NEAT)—MAB and NEAT are mutually exclusive. You cannot enable

MAB when NEAT is enabled on an interface, and you should not enable NEAT when MAB is enabled on an interface.

Cisco IOS Release 12.2(55)SE and later supports filtering of verbose MAB system messages

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Network Admission Control Layer 2 IEEE 802.1x Validation

Network Admission Control Layer 2 IEEE 802.1x Validation

The switch supports the Network Admission Control (NAC) Layer 2 IEEE 802.1x validation, which checks the antivirus condition or posture of endpoint systems or clients before granting the devices network access.

With NAC Layer 2 IEEE 802.1x validation, you can do these tasks:

• Download the Session-Timeout RADIUS attribute (Attribute[27]) and the Termination-Action RADIUS attribute (Attribute[29]) from the authentication server.

• Set the number of seconds between re-authentication attempts as the value of the Session-Timeout

RADIUS attribute (Attribute[27]) and get an access policy against the client from the RADIUS server.

• Set the action to be taken when the switch tries to re-authenticate the client by using the

Termination-Action RADIUS attribute (Attribute[29]). If the value is the DEFAULT or is not set, the session ends. If the value is RADIUS-Request, the re-authentication process starts.

• Set the list of VLAN number or name or VLAN group name as the value of the Tunnel Group Private

ID (Attribute[81]) and the preference for the VLAN number or name or VLAN group name as the value of the Tunnel Preference (Attribute[83]). If you do not configure the Tunnel Preference, the first Tunnel

Group Private ID (Attribute[81]) attribute is picked up from the list.

• View the NAC posture token, which shows the posture of the client, by using the show authentication privileged EXEC command.

• Configure secondary private VLANs as guest VLANs.

Configuring NAC Layer 2 IEEE 802.1x validation is similar to configuring IEEE 802.1x port-based authentication except that you must configure a posture token on the RADIUS server.

Flexible Authentication Ordering

You can use flexible authentication ordering to configure the order of methods that a port uses to authenticate a new host. The IEEE 802.1X Flexible Authentication feature supports three authentication methods:

• dot1X—IEEE 802.1X authentication is a Layer 2 authentication method.

• mab—MAC-Authentication Bypass is a Layer 2 authentication method.

• webauth—Web authentication is a Layer 3 authentication method.

Using this feature, you can control which ports use which authentication methods, and you can control the failover sequencing of methods on those ports. For example, MAC authentication bypass and 802.1x can be the primary or secondary authentication methods, and web authentication can be the fallback method if either or both of those authentication attempts fail.

The IEEE 802.1X Flexible Authentication feature supports the following host modes:

• multi-auth—Multiauthentication allows one authentication on a voice VLAN and multiple authentications on the data VLAN.

• multi-domain—Multidomain authentication allows two authentications: one on the voice VLAN and one on the data VLAN.

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Open1x Authentication

Related Topics

Configuring Flexible Authentication Ordering, on page 88

Open1x Authentication

Open1x authentication allows a device access to a port before that device is authenticated. When open authentication is configured, a new host can pass traffic according to the access control list (ACL) defined on the port. After the host is authenticated, the policies configured on the RADIUS server are applied to that host.

You can configure open authentication with these scenarios:

• Single-host mode with open authentication–Only one user is allowed network access before and after authentication.

• MDA mode with open authentication–Only one user in the voice domain and one user in the data domain are allowed.

• Multiple-hosts mode with open authentication–Any host can access the network.

• Multiple-authentication mode with open authentication–Similar to MDA, except multiple hosts can be authenticated.

Note

If open authentication is configured, it takes precedence over other authentication controls. This means that if you use the authentication open interface configuration command, the port will grant access to the host irrespective of the authentication

port-control interface configuration command.

Related Topics

Configuring Open1x, on page 90

Multidomain Authentication

The switch supports multidomain authentication (MDA), which allows both a data device and voice device, such as an IP phone (Cisco or non-Cisco), to authenticate on the same switch port. The port is divided into a data domain and a voice domain.

Note

For all host modes, the line protocol stays up before authorization when port-based authentication is configured.

MDA does not enforce the order of device authentication. However, for best results, we recommend that a voice device is authenticated before a data device on an MDA-enabled port.

Follow these guidelines for configuring MDA:

• You must configure a switch port for MDA.

• You must configure the voice VLAN for the IP phone when the host mode is set to multidomain.

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Limiting Login for Users

• Voice VLAN assignment on an MDA-enabled port is supported Cisco IOS Release 12.2(40)SE and later.

• To authorize a voice device, the AAA server must be configured to send a Cisco Attribute-Value (AV) pair attribute with a value of device-traffic-class=voice. Without this value, the switch treats the voice device as a data device.

• The guest VLAN and restricted VLAN features only apply to the data devices on an MDA-enabled port.

The switch treats a voice device that fails authorization as a data device.

• If more than one device attempts authorization on either the voice or the data domain of a port, it is error disabled.

• Until a device is authorized, the port drops its traffic. Non-Cisco IP phones or voice devices are allowed into both the data and voice VLANs. The data VLAN allows the voice device to contact a DHCP server to obtain an IP address and acquire the voice VLAN information. After the voice device starts sending on the voice VLAN, its access to the data VLAN is blocked.

• A voice device MAC address that is binding on the data VLAN is not counted towards the port security

MAC address limit.

• MDA can use MAC authentication bypass as a fallback mechanism to allow the switch port to connect to devices that do not support IEEE 802.1x authentication.

• When a data or a voice device is detected on a port, its MAC address is blocked until authorization succeeds. If the authorization fails, the MAC address remains blocked for 5 minutes.

• If more than five devices are detected on the data VLAN or more than one voice device is detected on the voice VLAN while a port is unauthorized, the port is error disabled.

• When a port host mode is changed from single- or multihost to multidomain mode, an authorized data device remains authorized on the port. However, a Cisco IP phone that has been allowed on the port voice VLAN is automatically removed and must be reauthenticated on that port.

• Active fallback mechanisms such as guest VLAN and restricted VLAN remain configured after a port changes from single- or multihost mode to multidomain mode.

• Switching a port host mode from multidomain to single- or multihost mode removes all authorized devices from the port.

• If a data domain is authorized first and placed in the guest VLAN, non-IEEE 802.1x-capable voice devices need to tag their packets on the voice VLAN to trigger authentication.

• We do not recommend per-user ACLs with an MDA-enabled port. An authorized device with a per-user

ACL policy might impact traffic on both the voice and data VLANs of the port. If used, only one device on the port should enforce per-user ACLs.

Limiting Login for Users

The Limiting Login feature helps Network administrators to limit the login attempt of users to a network.

When a user fails to successfully login to a network within a configurable number of attempts within a configurable time limit, the user can be blocked. This feature is enabled only for local users and not for remote users. You need to configure the aaa authentication rejected command in global configuration mode to enable this feature.

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802.1x Supplicant and Authenticator Switches with Network Edge Access Topology (NEAT)

802.1x Supplicant and Authenticator Switches with Network Edge Access

Topology (NEAT)

The Network Edge Access Topology (NEAT) feature extends identity to areas outside the wiring closet (such as conference rooms). This allows any type of device to authenticate on the port.

• 802.1x switch supplicant: You can configure a switch to act as a supplicant to another switch by using the 802.1x supplicant feature. This configuration is helpful in a scenario, where, for example, a switch is outside a wiring closet and is connected to an upstream switch through a trunk port. A switch configured with the 802.1x switch supplicant feature authenticates with the upstream switch for secure connectivity.

Once the supplicant switch authenticates successfully the port mode changes from access to trunk in an authenticator switch. In a supplicant switch you must manually configure trunk when enabling CISP.

• If the access VLAN is configured on the authenticator switch, it becomes the native VLAN for the trunk port after successful authentication.

In the default state, when you connect a supplicant switch to an authenticator switch that has BPDU guard enabled, the authenticator port could be error-disabled if it receives a Spanning Tree Protocol (STP) bridge protocol data unit (BPDU) packets before the supplicant switch has authenticated. Beginning with Cisco IOS

Release 15.0(1)SE, you can control traffic exiting the supplicant port during the authentication period. Entering the dot1x supplicant controlled transient global configuration command temporarily blocks the supplicant port during authentication to ensure that the authenticator port does not shut down before authentication completes. If authentication fails, the supplicant port opens. Entering the no dot1x supplicant controlled

transient global configuration command opens the supplicant port during the authentication period. This is the default behavior.

We strongly recommend using the dot1x supplicant controlled transientcommand on a supplicant switch when BPDU guard is enabled on the authenticator switch port with the spanning-tree bpduguard enable interface configuration command.

Note

If you globally enable BPDU guard on the authenticator switch by using the spanning-tree portfast

bpduguard default global configuration command, entering the dot1x supplicant controlled transient command does not prevent the BPDU violation.

You can enable MDA or multiauth mode on the authenticator switch interface that connects to one more supplicant switches. Multihost mode is not supported on the authenticator switch interface.

When you reboot an authenticator switch with single-host mode enabled on the interface, the interface may move to err-disabled state before authentication. To recover from err-disabled state, flap the authenticator port to activate the interface again and initiate authentication.

Use the dot1x supplicant force-multicast global configuration command on the supplicant switch for Network

Edge Access Topology (NEAT) to work in all host modes.

• Host Authorization: Ensures that only traffic from authorized hosts (connecting to the switch with supplicant) is allowed on the network. The switches use Client Information Signalling Protocol (CISP) to send the MAC addresses connecting to the supplicant switch to the authenticator switch.

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Voice Aware 802.1x Security

• Auto enablement: Automatically enables trunk configuration on the authenticator switch, allowing user traffic from multiple VLANs coming from supplicant switches. Configure the cisco-av-pair as

device-traffic-class=switch at the ACS. (You can configure this under the group or the user settings.)

Figure 5: Authenticator and Supplicant Switch using CISP

1

3

5

Workstations (clients)

Authenticator switch

Trunk port

2

4

Supplicant switch (outside wiring closet)

Access control server (ACS)

Note

The switchport nonegotiate command is not supported on supplicant and authenticator switches with

NEAT. This command should not be configured at the supplicant side of the topology. If configured on the authenticator side, the internal macros will automatically remove this command from the port.

Voice Aware 802.1x Security

Note

To use voice aware IEEE 802.1x authentication, the switch must be running the LAN base image.

You use the voice aware 802.1x security feature to configure the switch to disable only the VLAN on which a security violation occurs, whether it is a data or voice VLAN. In previous releases, when an attempt to authenticate the data client caused a security violation, the entire port shut down, resulting in a complete loss of connectivity.

You can use this feature in IP phone deployments where a PC is connected to the IP phone. A security violation found on the data VLAN results in the shutdown of only the data VLAN. The traffic on the voice VLAN flows through the switch without interruption.

Related Topics

Configuring Voice Aware 802.1x Security, on page 41

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Common Session ID

Common Session ID

Authentication manager uses a single session ID (referred to as a common session ID) for a client no matter which authentication method is used. This ID is used for all reporting purposes, such as the show commands and MIBs. The session ID appears with all per-session syslog messages.

The session ID includes:

• The IP address of the Network Access Device (NAD)

• A monotonically increasing unique 32 bit integer

• The session start time stamp (a 32 bit integer)

This example shows how the session ID appears in the output of the show authentication command. The session ID in this example is 160000050000000B288508E5:

Switch#

show authentication sessions

Interface MAC Address

Fa4/0/4 0000.0000.0203

Method mab

Domain

DATA

Status Session ID

Authz Success 160000050000000B288508E5

This is an example of how the session ID appears in the syslog output. The session ID in this example is also160000050000000B288508E5:

1w0d: %AUTHMGR-5-START: Starting 'mab' for client (0000.0000.0203) on Interface Fa4/0/4

AuditSessionID 160000050000000B288508E5

1w0d: %MAB-5-SUCCESS: Authentication successful for client (0000.0000.0203) on Interface

Fa4/0/4 AuditSessionID 160000050000000B288508E5

1w0d: %AUTHMGR-7-RESULT: Authentication result 'success' from 'mab' for client

(0000.0000.0203) on Interface Fa4/0/4 AuditSessionID 160000050000000B288508E5

The session ID is used by the NAD, the AAA server, and other report-analyzing applications to identify the client. The ID appears automatically. No configuration is required.

How to Configure 802.1x Port-Based Authentication

Default 802.1x Authentication Configuration

Table 4: Default 802.1x Authentication Configuration

Feature

Switch 802.1x enable state

Per-port 802.1x enable state

AAA

Default Setting

Disabled.

Disabled (force-authorized).

The port sends and receives normal traffic without

802.1x-based authentication of the client.

Disabled.


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Default 802.1x Authentication Configuration

Feature

RADIUS server

• IP address

• UDP authentication port

• Default accounting port

• Key

Host mode

Control direction

Periodic re-authentication

Number of seconds between re-authentication attempts

Re-authentication number

Quiet period

Retransmission time

Maximum retransmission number

Client timeout period

Authentication server timeout period

Inactivity timeout

Guest VLAN

Inaccessible authentication bypass

Default Setting

• None specified.

• 1645.

• 1646.

• None specified.

Single-host mode.

Bidirectional control.

Disabled.

3600 seconds.

2 times (number of times that the switch restarts the authentication process before the port changes to the unauthorized state).

60 seconds (number of seconds that the switch remains in the quiet state following a failed authentication exchange with the client).

30 seconds (number of seconds that the switch should wait for a response to an EAP request/identity frame from the client before resending the request).

2 times (number of times that the switch will send an

EAP-request/identity frame before restarting the authentication process).

30 seconds (when relaying a request from the authentication server to the client, the amount of time the switch waits for a response before resending the request to the client.)

30 seconds (when relaying a response from the client to the authentication server, the amount of time the switch waits for a reply before resending the response to the server.)

You can change this timeout period by using the dot1x timeout server-timeout interface configuration command.

Disabled.

None specified.

Disabled.

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802.1x Authentication Configuration Guidelines

Feature

Restricted VLAN

Authenticator (switch) mode

MAC authentication bypass

Voice-aware security

Default Setting

None specified.

None specified.

Disabled.

Disabled.


802.1x Authentication

These are the 802.1x authentication configuration guidelines:

• When 802.1x authentication is enabled, ports are authenticated before any other Layer 2 or Layer 3 features are enabled.

• If the VLAN to which an 802.1x-enabled port is assigned changes, this change is transparent and does not affect the switch. For example, this change occurs if a port is assigned to a RADIUS server-assigned

VLAN and is then assigned to a different VLAN after re-authentication.

If the VLAN to which an 802.1x port is assigned to shut down, disabled, or removed, the port becomes unauthorized. For example, the port is unauthorized after the access VLAN to which a port is assigned shuts down or is removed.

• The 802.1x protocol is supported on Layer 2 static-access ports, voice VLAN ports, and Layer 3 routed ports, but it is not supported on these port types:

◦Dynamic ports—A port in dynamic mode can negotiate with its neighbor to become a trunk port.

If you try to enable 802.1x authentication on a dynamic port, an error message appears, and 802.1x

authentication is not enabled. If you try to change the mode of an 802.1x-enabled port to dynamic, an error message appears, and the port mode is not changed.

◦EtherChannel port—Do not configure a port that is an active or a not-yet-active member of an

EtherChannel as an 802.1x port. If you try to enable 802.1x authentication on an EtherChannel port, an error message appears, and 802.1x authentication is not enabled.

◦Switched Port Analyzer (SPAN) and Remote SPAN (RSPAN) destination ports—You can enable

802.1x authentication on a port that is a SPAN or RSPAN destination port. However, 802.1x

authentication is disabled until the port is removed as a SPAN or RSPAN destination port. You can enable 802.1x authentication on a SPAN or RSPAN source port.

• Before globally enabling 802.1x authentication on a switch by entering the dot1x system-auth-control global configuration command, remove the EtherChannel configuration from the interfaces on which

802.1x authentication and EtherChannel are configured.

• Cisco IOS Release 12.2(55)SE and later supports filtering of system messages related to 802.1x

authentication.

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VLAN Assignment, Guest VLAN, Restricted VLAN, and Inaccessible Authentication Bypass

These are the configuration guidelines for VLAN assignment, guest VLAN, restricted VLAN, and inaccessible authentication bypass:

• When 802.1x authentication is enabled on a port, you cannot configure a port VLAN that is equal to a voice VLAN.

• The 802.1x authentication with VLAN assignment feature is not supported on trunk ports, dynamic ports, or with dynamic-access port assignment through a VMPS.

• You can configure any VLAN except an RSPAN VLAN or a voice VLAN as an 802.1x guest VLAN.

The guest VLAN feature is not supported on internal VLANs (routed ports) or trunk ports; it is supported only on access ports.

• After you configure a guest VLAN for an 802.1x port to which a DHCP client is connected, you might need to get a host IP address from a DHCP server. You can change the settings for restarting the 802.1x

authentication process on the switch before the DHCP process on the client times out and tries to get a host IP address from the DHCP server. Decrease the settings for the 802.1x authentication process

(authentication timer inactivity and authentication timer reauthentication interface configuration commands). The amount to decrease the settings depends on the connected 802.1x client type.

• When configuring the inaccessible authentication bypass feature, follow these guidelines:

◦The feature is supported on 802.1x port in single-host mode and multihosts mode.

◦If the client is running Windows XP and the port to which the client is connected is in the critical-authentication state, Windows XP might report that the interface is not authenticated.

◦If the Windows XP client is configured for DHCP and has an IP address from the DHCP server, receiving an EAP-Success message on a critical port might not re-initiate the DHCP configuration process.

◦You can configure the inaccessible authentication bypass feature and the restricted VLAN on an

802.1x port. If the switch tries to re-authenticate a critical port in a restricted VLAN and all the

RADIUS servers are unavailable, switch changes the port state to the critical authentication state and remains in the restricted VLAN.

◦If the CTS links are in Critical Authentication mode and the master reloads, the policy where SGT was configured on a device will not be available on the new master. This is because the internal bindings will not be synced to the standby switch in a 3750-X switch stack.

• You can configure any VLAN except an RSPAN VLAN or a voice VLAN as an 802.1x restricted VLAN.

The restricted VLAN feature is not supported on internal VLANs (routed ports) or trunk ports; it is supported only on access ports.

• When wireless guest clients obtains IP from foreign client VLAN instead of anchor client VLAN, you should use the ip dhcp required command under the WLAN configuration to force clients to issue a new DHCP request. This prevents the clients from getting an incorrect IP at anchor.

• If the wired guest clients fail to get IP address after a Cisco WLC (foreign) reload, perform a shut/no shut on the ports used by the clients to reconnect them.

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Configuring 802.1x Readiness Check

MAC Authentication Bypass

These are the MAC authentication bypass configuration guidelines:

• Unless otherwise stated, the MAC authentication bypass guidelines are the same as the 802.1x

authentication guidelines.

• If you disable MAC authentication bypass from a port after the port has been authorized with its MAC address, the port state is not affected.

• If the port is in the unauthorized state and the client MAC address is not the authentication-server database, the port remains in the unauthorized state. However, if the client MAC address is added to the database, the switch can use MAC authentication bypass to re-authorize the port.

• If the port is in the authorized state, the port remains in this state until re-authorization occurs.

• You can configure a timeout period for hosts that are connected by MAC authentication bypass but are inactive. The range is 1to 65535 seconds.

Maximum Number of Allowed Devices Per Port

This is the maximum number of devices allowed on an 802.1x-enabled port:

• In single-host mode, only one device is allowed on the access VLAN. If the port is also configured with a voice VLAN, an unlimited number of Cisco IP phones can send and receive traffic through the voice

VLAN.

• In multidomain authentication (MDA) mode, one device is allowed for the access VLAN, and one IP phone is allowed for the voice VLAN.

• In multihost mode, only one 802.1x supplicant is allowed on the port, but an unlimited number of non-802.1x hosts are allowed on the access VLAN. An unlimited number of devices are allowed on the voice VLAN.


The 802.1x readiness check monitors 802.1x activity on all the switch ports and displays information about the devices connected to the ports that support 802.1x. You can use this feature to determine if the devices connected to the switch ports are 802.1x-capable.

The 802.1x readiness check is allowed on all ports that can be configured for 802.1x. The readiness check is not available on a port that is configured as dot1x force-unauthorized.

Follow these steps to enable the 802.1x readiness check on the switch:

Before You Begin

Follow these guidelines to enable the readiness check on the switch:

• The readiness check is typically used before 802.1x is enabled on the switch.

• If you use the dot1x test eapol-capable privileged EXEC command without specifying an interface, all the ports on the switch stack are tested.

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• When you configure the dot1x test eapol-capable command on an 802.1x-enabled port, and the link comes up, the port queries the connected client about its 802.1x capability. When the client responds with a notification packet, it is 802.1x-capable. A syslog message is generated if the client responds within the timeout period. If the client does not respond to the query, the client is not 802.1x-capable.

No syslog message is generated

• When you configure the dot1x test eapol-capable command on an 802.1x-enabled port, and the link comes up, the port queries the connected client about its 802.1x capability. When the client responds with a notification packet, it is 802.1x-capable. A syslog message is generated if the client responds within the timeout period. If the client does not respond to the query, the client is not 802.1x-capable.

No syslog message is generated

• The readiness check can be sent on a port that handles multiple hosts (for example, a PC that is connected to an IP phone). A syslog message is generated for each of the clients that respond to the readiness check within the timer period.

SUMMARY STEPS

1. enable

2. configure terminal

3. dot1x test eapol-capable [interface interface-id]

4. dot1x test timeout timeout

5. end

6. show running-config

7. copy running-config startup-config

DETAILED STEPS

Step 1

Step 2

Step 3

Command or Action enable

Purpose

Enables privileged EXEC mode. Enter your password if prompted.

Example:

Switch>

enable configure terminal

Enters the global configuration mode.

Example:

Switch#

configure terminal

dot1x test eapol-capable [interface interface-id] Enables the 802.1x readiness check on the switch.

Example:

Switch#

dot1x test eapol-capable interface gigabitethernet1/0/13

DOT1X_PORT_EAPOL_CAPABLE:DOT1X: MAC

00-01-02-4b-f1-a3 on gigabitethernet1/0/13 is

EAPOL capable

(Optional) For interface-id specify the port on which to check for IEEE 802.1x readiness.

Note

If you omit the optional interface keyword, all interfaces on the switch are tested.

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Configuring Voice Aware 802.1x Security

Step 4

Step 5

Step 6

Step 7

Command or Action

dot1x test timeout timeout

end

Example:

Switch(config)#

end show running-config

Example:

Switch#

show running-config copy running-config startup-config

Example:

Switch#

copy running-config startup-config

Purpose

(Optional) Configures the timeout used to wait for EAPOL response. The range is from 1 to 65535 seconds. The default is 10 seconds.

Returns to privileged EXEC mode.

Verifies your entries.

(Optional) Saves your entries in the configuration file.

Related Topics

802.1x Readiness Check, on page 16


Note

To use voice aware IEEE 802.1x authentication, the switch must be running the LAN base image.

You use the voice aware 802.1x security feature on the switch to disable only the VLAN on which a security violation occurs, whether it is a data or voice VLAN. You can use this feature in IP phone deployments where a PC is connected to the IP phone. A security violation found on the data VLAN results in the shutdown of only the data VLAN. The traffic on the voice VLAN flows through the switch without interruption.

Follow these guidelines to configure voice aware 802.1x voice security on the switch:

• You enable voice aware 802.1x security by entering the errdisable detect cause security-violation

shutdown vlan global configuration command. You disable voice aware 802.1x security by entering the no version of this command. This command applies to all 802.1x-configured ports in the switch.

Note

If you do not include the shutdown vlan keywords, the entire port is shut down when it enters the error-disabled state.

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41



• If you use the errdisable recovery cause security-violation global configuration command to configure error-disabled recovery, the port is automatically re-enabled. If error-disabled recovery is not configured for the port, you re-enable it by using the shutdown and no shutdown interface configuration commands.

• You can re-enable individual VLANs by using the clear errdisable interface interface-id vlan [vlan-list] privileged EXEC command. If you do not specify a range, all VLANs on the port are enabled.

Beginning in privileged EXEC mode, follow these steps to enable voice aware 802.1x security:

SUMMARY STEPS


2. errdisable detect cause security-violation shutdown vlan

3. errdisable recovery cause security-violation

4. clear errdisable interfaceinterface-id vlan [vlan-list]

5. Enter the following:

• shutdown

• no shutdown

6. end

7. show errdisable detect

DETAILED STEPS

Step 1

Step 2

Step 3

Step 4

Step 5

Step 6

Command or Action configure terminal

Purpose

Enter global configuration mode.

errdisable detect cause security-violation shutdown vlan

Shut down any VLAN on which a security violation error occurs.

errdisable recovery cause security-violation

Note

If the shutdown vlan keywords are not included, the entire port enters the error-disabled state and shuts down.

Enter global configuration mode.

clear errdisable interfaceinterface-id vlan

[vlan-list]

(Optional) Reenable individual VLANs that have been error disabled.

• For interface-id specify the port on which to reenable individual

VLANs.

• (Optional) For vlan-list specify a list of VLANs to be re-enabled.

If vlan-list is not specified, all VLANs are re-enabled.

Enter the following:

• shutdown

• no shutdown

(Optional) Re-enable an error-disabled VLAN, and clear all error-disable indications.

end

Return to privileged EXEC mode.

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Configuring 802.1x Violation Modes

Step 7

Command or Action show errdisable detect

Purpose

Verify your entries.

This example shows how to configure the switch to shut down any VLAN on which a security violation error occurs:

Switch(config)#

errdisable detect cause security-violation shutdown vlan

This example shows how to re-enable all VLANs that were error disabled on port Gigabit Ethernet 40/2.

Switch#

vlan clear errdisable interface gigabitethernet4/0/2

You can verify your settings by entering the show errdisable detect privileged EXEC command.

Related Topics

Voice Aware 802.1x Security, on page 34


You can configure an 802.1x port so that it shuts down, generates a syslog error, or discards packets from a new device when:

• a device connects to an 802.1x-enabled port

• the maximum number of allowed about devices have been authenticated on the port

Beginning in privileged EXEC mode, follow these steps to configure the security violation actions on the switch:

SUMMARY STEPS


2. aaa new-model

3. aaa authentication dot1x {default} method1

4. interface interface-id

5. switchport mode access

6. authentication violation {shutdown | restrict | protect | replace}

7. end

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DETAILED STEPS

Step 1

Step 2

Step 3

Step 4

Step 5


Purpose


Example:

Switch#

configure terminal aaa new-model

Enables AAA.

Example:

Switch(config)#

aaa new-model

aaa authentication dot1x {default} method1

Example:

Switch(config)#

aaa authentication dot1x default group radius

Creates an 802.1x authentication method list.

To create a default list that is used when a named list is not specified in the authentication command, use the default keyword followed by the method that is to be used in default situations. The default method list is automatically applied to all ports.

For method1, enter the group radius keywords to use the list of all

RADIUS servers for authentication.

interface interface-id Specifies the port connected to the client that is to be enabled for

IEEE 802.1x authentication, and enter interface configuration mode.

Example:

Switch(config)#

interface gigabitethernet1/0/4 switchport mode access

Sets the port to access mode.

Example:

Switch(config-if)#

switchport mode access

Step 6

authentication violation {shutdown | restrict |

protect | replace}

Configures the violation mode. The keywords have these meanings:

• shutdown–Error disable the port.

Example:

Switch(config-if)#

authentication violation restrict

• restrict–Generate a syslog error.

• protect–Drop packets from any new device that sends traffic to the port.

• replace–Removes the current session and authenticates with the new host.

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Configuring 802.1x Authentication

Step 7

Command or Action end

Example:

Switch(config-if)#

end

Purpose


Configuring 802.1x Authentication

To allow per-user ACLs or VLAN assignment, you must enable AAA authorization to configure the switch for all network-related service requests.

This is the 802.1x AAA process:


To configure 802.1x port-based authentication, you must enable authentication, authorization, and accounting

(AAA) and specify the authentication method list. A method list describes the sequence and authentication method to be queried to authenticate a user.

SUMMARY STEPS

1. A user connects to a port on the switch.

2. Authentication is performed.

3. VLAN assignment is enabled, as appropriate, based on the RADIUS server configuration.

4. The switch sends a start message to an accounting server.

5. Re-authentication is performed, as necessary.

6. The switch sends an interim accounting update to the accounting server that is based on the result of re-authentication.

7. The user disconnects from the port.

8. The switch sends a stop message to the accounting server.

DETAILED STEPS

Step 1

Step 2

Step 3

Step 4

Step 5


A user connects to a port on the switch.

Authentication is performed.

VLAN assignment is enabled, as appropriate, based on the RADIUS server configuration.

The switch sends a start message to an accounting server.

Re-authentication is performed, as necessary.

Purpose

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Configuring 802.1x Port-Based Authentication

Step 6

Step 7

Step 8


The switch sends an interim accounting update to the accounting server that is based on the result of re-authentication.

The user disconnects from the port.

The switch sends a stop message to the accounting server.

Purpose


Beginning in privileged EXEC mode, follow these steps to configure 802.1x port-based authentication:

SUMMARY STEPS



3. aaa authentication dot1x {default} method1

4. dot1x system-auth-control

5. aaa authorization network {default} group radius

6. radius-server host ip-address

7. radius-server key string



10. authentication port-control auto

11. dot1x pae authenticator

12. end

DETAILED STEPS

Step 1

Step 2

Step 3


Example:

Switch#

configure terminal aaa new-model

Example:

Switch(config)#

aaa new-model

aaa authentication dot1x {default} method1

Purpose


Enables AAA.

Creates an 802.1x authentication method list.

46


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Step 4

Step 5

Step 6

Step 7

Step 8


Example:

Switch(config)#

aaa authentication dot1x default group radius dot1x system-auth-control

Purpose

To create a default list that is used when a named list is not specified in the authentication command, use the default keyword followed by the method that is to be used in default situations. The default method list is automatically applied to all ports.

For method1, enter the group radius keywords to use the list of all RADIUS servers for authentication.

Note

Though other keywords are visible in the command-line help string, only the group radius keywords are supported.

Enables 802.1x authentication globally on the switch.

Example:

Switch(config)#

dot1x system-auth-control

aaa authorization network {default} group

radius

Example:

Switch(config)#

aaa authorization network default group radius

(Optional) Configures the switch to use user-RADIUS authorization for all network-related service requests, such as per-user ACLs or VLAN assignment.

radius-server host ip-address

(Optional) Specifies the IP address of the RADIUS server.

Example:

Switch(config)#

radius-server host

124.2.2.12

radius-server key string

Example:

Switch(config)#

radius-server key abc1234

(Optional) Specifies the authentication and encryption key used between the switch and the RADIUS daemon running on the

RADIUS server.

interface interface-id Specifies the port connected to the client that is to be enabled for

IEEE 802.1x authentication, and enter interface configuration mode.

Example:

Switch(config)#

interface gigabitethernet1/0/2

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Configuring the Switch-to-RADIUS-Server Communication

Step 9

Step 10

Step 11

Step 12

Command or Action switchport mode access

Example:

Switch(config-if)#


Purpose

(Optional) Sets the port to access mode only if you configured the RADIUS server in Step 6 and Step 7.

authentication port-control auto

Enables 802.1x authentication on the port.

Example:

Switch(config-if)#

authentication port-control auto dot1x pae authenticator

Example:

Switch(config-if)#

dot1x pae authenticator

Sets the interface Port Access Entity to act only as an authenticator and ignore messages meant for a supplicant.


end

Example:

Switch(config-if)#

end


You can globally configure the timeout, retransmission, and encryption key values for all RADIUS servers by using the radius-server host global configuration command. If you want to configure these options on a per-server basis, use the radius-server timeout, the radius-server retransmit, and the radius-server key global configuration commands.

You also need to configure some settings on the RADIUS server. These settings include the IP address of the switch and the key string to be shared by both the server and the switch. For more information, see the RADIUS server documentation.

Follow these steps to configure the RADIUS server parameters on the switch. This procedure is required.


You must enable authentication, authorization, and accounting (AAA) and specify the authentication method list. A method list describes the sequence and authentication method to be queried to authenticate a user.

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SUMMARY STEPS

1. enable


3. radius-server host {hostname | ip-address} auth-port port-number key string

4. end

DETAILED STEPS

Step 1

Step 2

Step 3

Step 4


Purpose

Enables privileged EXEC mode. Enter your password if prompted.

Example:

Switch>

enable configure terminal


Example:

Switch#


radius-server host {hostname |

ip-address} auth-port port-number key

string

Configures the RADIUS server parameters.

For hostname | ip-address, specify the server name or IP address of the remote

RADIUS server.

Example:

For auth-port port-number, specify the UDP destination port for authentication requests. The default is 1645. The range is 0 to 65536.

Switch(config)#


125.5.5.43 auth-port 1645 key rad123

For key string, specify the authentication and encryption key used between the switch and the RADIUS daemon running on the RADIUS server. The key is a text string that must match the encryption key used on the RADIUS server.

Note

Always configure the key as the last item in the radius-server host command syntax because leading spaces are ignored, but spaces within and at the end of the key are used. If you use spaces in the key, do not enclose the key in quotation marks unless the quotation marks are part of the key. This key must match the encryption used on the RADIUS daemon.

If you want to use multiple RADIUS servers, re-enter this command.

end


Example:

Switch(config)#

end

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Configuring the Host Mode

Related Topics

Switch-to-RADIUS-Server Communication, on page 16

Configuring the Host Mode

Beginning in privileged EXEC mode, follow these steps to allow multiple hosts (clients) on an

IEEE 802.1x-authorized port that has the authentication port-control interface configuration command set to auto. Use the multi-domain keyword to configure and enable multidomain authentication (MDA), which allows both a host and a voice device, such as an IP phone (Cisco or non-Cisco), on the same switch port.

This procedure is optional.

SUMMARY STEPS



3. authentication host-mode [multi-auth | multi-domain | multi-host | single-host]

4. end

DETAILED STEPS

Step 1

Step 2

Step 3


Purpose


Example:

Switch#


interface interface-id Specifies the port to which multiple hosts are indirectly attached, and enter interface configuration mode.

Example:

Switch(config)#


authentication host-mode [multi-auth |

multi-domain | multi-host | single-host]

Allows multiple hosts (clients) on an 802.1x-authorized port.

The keywords have these meanings:

Example:

Switch(config-if)#

authentication host-mode multi-host

• multi-auth–Allow one client on the voice VLAN and multiple authenticated clients on the data VLAN.

Note

The multi-auth keyword is only available with the

authentication host-mode command.

• multi-host–Allow multiple hosts on an 802.1x-authorized port after a single host has been authenticated.

• multi-domain–Allow both a host and a voice device, such as an IP phone (Cisco or non-Cisco), to be authenticated on an

IEEE 802.1x-authorized port.

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Configuring Periodic Re-Authentication

Command or Action Purpose

Note

You must configure the voice VLAN for the IP phone when the host mode is set to multi-domain.

Make sure that the authentication port-control interface configuration command is set to auto for the specified interface.


Step 4 end

Example:

Switch(config-if)#

end

Configuring Periodic Re-Authentication

You can enable periodic 802.1x client re-authentication and specify how often it occurs. If you do not specify a time period before enabling re-authentication, the number of seconds between attempts is 3600.

Beginning in privileged EXEC mode, follow these steps to enable periodic re-authentication of the client and to configure the number of seconds between re-authentication attempts. This procedure is optional.

SUMMARY STEPS



3. authentication periodic

4. authentication timer {{[inactivity | reauthenticate | restart | unauthorized]} {value}}

5. end

DETAILED STEPS

Step 1

Step 2


Example:

Switch#


interface interface-id

Example:

Switch(config)#


Purpose


Specifies the port to be configured, and enter interface configuration mode.

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Changing the Quiet Period

Step 3

Step 4

Step 5

Command or Action authentication periodic

Example:

Switch(config-if)#

authentication periodic

authentication timer {{[inactivity |

reauthenticate | restart | unauthorized]}

{value}}

Example:

Switch(config-if)#

authentication timer reauthenticate 180

Purpose

Enables periodic re-authentication of the client, which is disabled by default.

Note

The default value is 3600 seconds. To change the value of the reauthentication timer or to have the switch use a

RADIUS-provided session timeout, enter the authentication

timer reauthenticate command.

Sets the number of seconds between re-authentication attempts.

The authentication timer keywords have these meanings:

• inactivity—Interval in seconds after which if there is no activity from the client then it is unauthorized

• reauthenticate—Time in seconds after which an automatic re-authentication attempt is initiated

• restart value—Interval in seconds after which an attempt is made to authenticate an unauthorized port

• unauthorized value—Interval in seconds after which an unauthorized session will get deleted

end

This command affects the behavior of the switch only if periodic re-authentication is enabled.


Example:

Switch(config-if)#

end


When the switch cannot authenticate the client, the switch remains idle for a set period of time and then tries again. The authentication timer inactivity interface configuration command controls the idle period. A failed authentication of the client might occur because the client provided an invalid password. You can provide a faster response time to the user by entering a number smaller than the default.

Beginning in privileged EXEC mode, follow these steps to change the quiet period. This procedure is optional.

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SUMMARY STEPS



3. authentication timer inactivity seconds

4. end

5. show authentication sessions interface interface-id


DETAILED STEPS

Step 1

Step 2

Step 3

Step 4

Step 5

Step 6


Purpose


Example:

Switch#


interface interface-id Specifies the port to be configured, and enter interface configuration mode.

Example:

Switch(config)#


authentication timer inactivity seconds Sets the number of seconds that the switch remains in the quiet state following a failed authentication exchange with the client.

Example:

Switch(config-if)#

authentication timer inactivity

30

The range is 1 to 65535 seconds; the default is 60.

end


Example:

Switch(config-if)#

end

show authentication sessions interface interface-id Verifies your entries.

Example:

Switch#

show authentication sessions interface gigabitethernet2/0/1 copy running-config startup-config


Example:

Switch#


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Changing the Switch-to-Client Retransmission Time

Changing the Switch-to-Client Retransmission Time

The client responds to the EAP-request/identity frame from the switch with an EAP-response/identity frame.

If the switch does not receive this response, it waits a set period of time (known as the retransmission time) and then resends the frame.

Note

You should change the default value of this command only to adjust for unusual circumstances such as unreliable links or specific behavioral problems with certain clients and authentication servers.

Beginning in privileged EXEC mode, follow these steps to change the amount of time that the switch waits for client notification. This procedure is optional.

SUMMARY STEPS



3. authentication timer reauthenticate seconds

4. end



DETAILED STEPS

Step 1

Step 2

Step 3


Purpose


Example:

Switch#



Example:

Switch(config)#


authentication timer reauthenticate seconds

Example:

Switch(config-if)#

authentication timer reauthenticate 60

Sets the number of seconds that the switch waits for a response to an EAP-request/identity frame from the client before resending the request.

The range is 1 to 65535 seconds; the default is 5.

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Setting the Switch-to-Client Frame-Retransmission Number

Step 4

Step 5

Step 6


Purpose


Example:

Switch(config-if)#

end


Example:

Switch#



Example:

Switch#


Setting the Switch-to-Client Frame-Retransmission Number

In addition to changing the switch-to-client retransmission time, you can change the number of times that the switch sends an EAP-request/identity frame (assuming no response is received) to the client before restarting the authentication process.

Note


Beginning in privileged EXEC mode, follow these steps to set the switch-to-client frame-retransmission number. This procedure is optional.

SUMMARY STEPS



3. dot1x max-reauth-req count

4. end

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Setting the Re-Authentication Number

DETAILED STEPS

Step 1

Step 2

Step 3

Step 4


Purpose


Example:

Switch#



Example:

Switch(config)#


dot1x max-reauth-req count

Example:

Switch(config-if)#

dot1x max-reauth-req 5 end

Sets the number of times that the switch sends an

EAP-request/identity frame to the client before restarting the authentication process. The range is 1 to 10; the default is 2.


Example:

Switch(config-if)#

end

Setting the Re-Authentication Number

You can also change the number of times that the switch restarts the authentication process before the port changes to the unauthorized state.

Note


Beginning in privileged EXEC mode, follow these steps to set the re-authentication number. This procedure is optional.

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Enabling MAC Move

SUMMARY STEPS




4. dot1x max-req count

5. end

DETAILED STEPS

Step 1

Step 2

Step 3

Step 4

Step 5


Purpose


Example:

Switch#




Example:

Switch#


Sets the port to access mode only if you previously configured the RADIUS server.

Example:

Switch(config-if)#


dot1x max-req count Sets the number of times that the switch restarts the authentication process before the port changes to the unauthorized state. The range is 0 to 10; the default is 2.

Example:

Switch(config-if)#

dot1x max-req 4 end


Example:

Switch(config-if)#

end


MAC move allows an authenticated host to move from one port on the switch to another.

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Beginning in privileged EXEC mode, follow these steps to globally enable MAC move on the switch. This procedure is optional.

SUMMARY STEPS


2. authentication mac-move permit

3. end



DETAILED STEPS

Step 1

Step 2

Step 3

Step 4

Step 5


Purpose

Enters global configuration mode.

Example:

Switch#

configure terminal authentication mac-move permit

Example:

Switch(config)#

authentication mac-move permit end

Enables MAC move on the switch. Default is deny.

In Session Aware Networking mode, the default CLI is

access-session mac-move deny. To enable Mac Move in Session

Aware Networking, use the no access-session mac-move global configuration command.

In legacy mode (IBNS 1.0), default value for mac-move is deny and in C3PL mode (IBNS 2.0) default value is permit.


Example:

Switch(config)#



Example:

Switch#



Example:

Switch#


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Enabling MAC Replace

Enabling MAC Replace

MAC replace allows a host to replace an authenticated host on a port.

Beginning in privileged EXEC mode, follow these steps to enable MAC replace on an interface. This procedure is optional.

SUMMARY STEPS



3. authentication violation {protect | replace | restrict | shutdown}

4. end



DETAILED STEPS

Step 1

Step 2

Step 3


Purpose


Example:

Switch#



Example:

Switch(config)#


authentication violation {protect | replace |

restrict | shutdown}

Example:

Switch(config-if)#

authentication violation replace

Use the replace keyword to enable MAC replace on the interface.

The port removes the current session and initiates authentication with the new host.

The other keywords have these effects:

• protect: the port drops packets with unexpected MAC addresses without generating a system message.

• restrict: violating packets are dropped by the CPU and a system message is generated.

• shutdown: the port is error disabled when it receives an unexpected MAC address.

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Configuring 802.1x Accounting

Step 4

Step 5

Step 6


Example:

Switch(config-if)#


Purpose



Example:

Switch#


Example:

Switch#




Enabling AAA system accounting with 802.1x accounting allows system reload events to be sent to the accounting RADIUS server for logging. The server can then infer that all active 802.1x sessions are closed.

Because RADIUS uses the unreliable UDP transport protocol, accounting messages might be lost due to poor network conditions. If the switch does not receive the accounting response message from the RADIUS server after a configurable number of retransmissions of an accounting request, this system message appears:

Accounting message %s for session %s failed to receive Accounting Response.

When the stop message is not sent successfully, this message appears:

00:09:55: %RADIUS-4-RADIUS_DEAD: RADIUS server 172.20.246.201:1645,1646 is not responding.

Note

You must configure the RADIUS server to perform accounting tasks, such as logging start, stop, and interim-update messages and time stamps. To turn on these functions, enable logging of “Update/Watchdog packets from this AAA client” in your RADIUS server Network Configuration tab. Next, enable “CVS

RADIUS Accounting” in your RADIUS server System Configuration tab.

Beginning in privileged EXEC mode, follow these steps to configure 802.1x accounting after AAA is enabled on your switch. This procedure is optional.

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SUMMARY STEPS



3. aaa accounting dot1x default start-stop group radius

4. aaa accounting system default start-stop group radius

5. end



DETAILED STEPS

Step 1

Step 2

Step 3

Step 4

Step 5


Purpose


Example:

Switch#



Example:

Switch(config)#

interface gigabitethernet1/0/3 aaa accounting dot1x default start-stop group radius

Enables 802.1x accounting using the list of all

RADIUS servers.

Example:

Switch(config-if)#

aaa accounting dot1x default start-stop group radius aaa accounting system default start-stop group radius

Example:

Switch(config-if)#

aaa accounting system default start-stop group radius

(Optional) Enables system accounting (using the list of all RADIUS servers) and generates system accounting reload event messages when the switch reloads.

end

Returns to privileged EXEc mode.

Example:

Switch(config-if)#

end

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61


Configuring a Guest VLAN

Step 6

Step 7

Command or Action show running-config

Example:

Switch#


Example:

Switch#


Purpose



Configuring a Guest VLAN

When you configure a guest VLAN, clients that are not 802.1x-capable are put into the guest VLAN when the server does not receive a response to its EAP request/identity frame. Clients that are 802.1x-capable but that fail authentication are not granted network access. The switch supports guest VLANs in single-host or multiple-hosts mode.

Beginning in privileged EXEC mode, follow these steps to configure a guest VLAN. This procedure is optional.

SUMMARY STEPS



3. Use one of the following:

• switchport mode access

• switchport mode private-vlan host

4. authentication event no-response action authorize vlan vlan-id

5. end

DETAILED STEPS

Step 1


Example:

Switch#


Purpose


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Configuring a Restricted VLAN

Step 2

Step 3

Step 4

Step 5



Example:

Switch(config)#


Use one of the following:



Purpose


• Sets the port to access mode.

• Configures the Layer 2 port as a private-VLAN host port.

Example:

Switch(config-if)#

switchport mode private-vlan host authentication event no-response action authorize vlan

vlan-id

Specifies an active VLAN as an 802.1x guest VLAN. The range is 1 to 4094.

Example:

You can configure any active VLAN except an internal

VLAN (routed port), an RSPAN VLAN or a voice VLAN as an 802.1x guest VLAN.

Switch(config-if)#

authentication event no-response action authorize vlan 2 end


Example:

Switch(config-if)#

end


When you configure a restricted VLAN on a switch stack or a switch, clients that are IEEE 802.1x-compliant are moved into the restricted VLAN when the authentication server does not receive a valid username and password. The switch supports restricted VLANs only in single-host mode.

Beginning in privileged EXEC mode, follow these steps to configure a restricted VLAN. This procedure is optional.

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SUMMARY STEPS







5. authentication event fail action authorize vlan vlan-id

6. end

DETAILED STEPS

Step 1

Step 2

Step 3


Purpose


Example:

Switch#



Example:

Switch(config)#








Step 4

Example:

Switch(config-if)#

switchport mode access authentication port-control auto

Example:

Switch(config-if)#



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Step 5

Step 6


authentication event fail action authorize vlan vlan-id Specifies an active VLAN as an 802.1x restricted VLAN.

The range is 1 to 4094.

Example:

Switch(config-if)#

authentication event fail action authorize vlan 2


VLAN (routed port), an RSPAN VLAN or a voice VLAN as an 802.1x restricted VLAN.

end


Example:

Switch(config-if)#

end

Configuring Number of Authentication Attempts on a Restricted VLAN

You can configure the maximum number of authentication attempts allowed before a user is assigned to the restricted VLAN by using the authentication event retry retry count interface configuration command. The range of allowable authentication attempts is 1 to 3. The default is 3 attempts.

Beginning in privileged EXEC mode, follow these steps to configure the maximum number of allowed authentication attempts. This procedure is optional.

SUMMARY STEPS







5. authentication event fail action authorize vlan vlan-id

6. authentication event retry retry count

7. end

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65



DETAILED STEPS

Step 1

Step 2

Step 3


Purpose


Example:

Switch#



Example:

Switch(config)#








Step 4

Step 5

Step 6

Example:

or

Switch(config-if)#



Example:

Switch(config-if)#


authentication event fail action authorize vlan vlan-id Specifies an active VLAN as an 802.1x restricted VLAN.

The range is 1 to 4094.

Example:

Switch(config-if)#

authentication event fail action authorize vlan 8


VLAN (routed port), an RSPAN VLAN or a voice VLAN as an 802.1x restricted VLAN.

authentication event retry retry count

Example:

Switch(config-if)#

authentication event retry

2

Specifies a number of authentication attempts to allow before a port moves to the restricted VLAN. The range is

1 to 3, and the default is 3.

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Configuring 802.1x Inaccessible Authentication Bypass with Critical Voice VLAN

Step 7


Example:

Switch(config-if)#

end

Purpose


Configuring 802.1x Inaccessible Authentication Bypass with Critical Voice

VLAN

Beginning in privileged EXEC mode, follow these steps to configure critical voice VLAN on a port and enable the inaccessible authentication bypass feature.

SUMMARY STEPS



3. radius-server dead-criteria{time seconds } [tries number]

4. radius-serverdeadtimeminutes

5. radius-server host ip-address address[acct-port udp-port][auth-port udp-port] [testusername

name[idle-time time] [ignore-acct-port][ignore auth-port]] [key string]

6. dot1x critical {eapol | recovery delay milliseconds}


8. authentication event server dead action {authorize | reinitialize} vlan vlan-id]

9. switchport voice vlan vlan-id

10. authentication event server dead action authorize voice

11. show authentication interface interface-id


DETAILED STEPS

Step 1


Example:

Switch#


Purpose


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67



Step 2

Step 3

Step 4

Step 5

Command or Action aaa new-model

Purpose

Enables AAA.

Example:

Switch(config)#

aaa new-model

radius-server dead-criteria{time seconds }

[tries number]

Sets the conditions that determine when a RADIUS server is considered un-available or down (dead).

Example:

Switch(config)#

radius-server dead-criteria time 20 tries 10

• time— 1 to 120 seconds. The switch dynamically determines a default seconds value between 10 and 60.

• number—1 to 100 tries. The switch dynamically determines a default

triesnumber between 10 and 100.

radius-serverdeadtimeminutes

Example:

Switch(config)#

radius-server deadtime

60

(Optional) Sets the number of minutes during which a RADIUS server is not sent requests. The range is from 0 to 1440 minutes (24 hours). The default is 0 minutes.

radius-server host ip-address

address[acct-port udp-port][auth-port

udp-port] [testusername name[idle-time time]

[ignore-acct-port][ignore auth-port]] [key

string]

(Optional) Configure the RADIUS server parameters by using these keywords:

• acct-portudp-port—Specify the UDP port for the RADIUS accounting server. The range for the UDP port number is from 0 to

65536. The default is 1646.

Example:

Switch(config)#


1.1.1.2 acct-port 1550 auth-port

1560 test username user1 idle-time 30 key abc1234

• auth-portudp-port—Specify the UDP port for the RADIUS authentication server. The range for the UDP port number is from 0 to 65536. The default is 1645.

Note

You should configure the UDP port for the RADIUS accounting server and the UDP port for the RADIUS authentication server to nondefault values.

• test usernamename—Enable automated testing of the RADIUS server status, and specify the username to be used.

• idle-time time—Set the interval of time in minutes after which the switch sends test packets to the server. The range is from 1 to 35791 minutes. The default is 60 minutes (1 hour).

• ignore-acct-port—Disable testing on the RADIUS-server accounting port.

• ignore-auth-port—Disable testing on the RADIUS-server authentication port.

• For keystring, specify the authentication and encryption key used between the switch and the RADIUS daemon running on the

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Step 6

Step 7

Step 8

Step 9


RADIUS server. The key is a text string that must match the encryption key used on the RADIUS server.

Note

Always configure the key as the last item in the

radius-server host command syntax because leading spaces are ignored, but spaces within and at the end of the key are used. If you use spaces in the key, do not enclose the key in quotation marks unless the quotation marks are part of the key. This key must match the encryption used on the

RADIUS daemon.

You can also configure the authentication and encryption key by using theradius-server key {0string | 7string | string} global configuration command.

dot1x critical {eapol | recovery delay

milliseconds}

Example:

Switch(config)#

dot1x critical eapol

(config)#

dot1x critical recovery delay

2000

(Optional) Configure the parameters for inaccessible authentication bypass:

• eapol—Specify that the switch sends an EAPOL-Success message when the switch successfully authenticates the critical port.

• recovery delaymilliseconds—Set the recovery delay period during which the switch waits to re-initialize a critical port when a RADIUS server that was unavailable becomes available. The range is from 1 to 10000 milliseconds. The default is 1000 milliseconds (a port can be re-initialized every second).

interface interface-id Specify the port to be configured, and enter interface configuration mode.

Example:

Switch(config)#

interface gigabitethernet 1/0/1 authentication event server dead action

{authorize | reinitialize} vlan vlan-id]

Example:

Switch(config-if)#

authentication event server dead action reinitialicze vlan 20

Use these keywords to move hosts on the port if the RADIUS server is unreachable:

• authorize—Move any new hosts trying to authenticate to the user-specified critical VLAN.

• reinitialize—Move all authorized hosts on the port to the user-specified critical VLAN.

switchport voice vlan vlan-id

Example:

Switch(config-if)#

switchport voice vlan

Specifies the voice VLAN for the port. The voice VLAN cannot be the same as the critical data VLAN configured in Step 6.

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Step 10

Step 11

Command or Action authentication event server dead action authorize voice

Purpose

Configures critical voice VLAN to move data traffic on the port to the voice VLAN if the RADIUS server is unreachable.

Example:

Switch(config-if)#

authentication event server dead action authorize voice

show authentication interface interface-id (Optional) Verify your entries.

Example:

Switch(config-if)#

do show authentication interface gigabit 1/0/1

Step 12 copy running-config startup-config

Example:

Switch(config-if)#

do copy running-config startup-config

(Optional) Verify your entries.

To return to the RADIUS server default settings, use the no radius-server dead-criteria, the no radius-server

deadtime, and the no radius-server host global configuration commands. To disable inaccessible authentication bypass, use the no authentication event server dead action interface configuration command. To disable critical voice VLAN, use the no authentication event server dead action authorize voice interface configuration command.

Example of Configuring Inaccessible Authentication Bypass

This example shows how to configure the inaccessible authentication bypass feature:

Switch(config)#

radius-server dead-criteria time 30 tries 20

Switch(config)#

radius-server deadtime 60

Switch(config)#

radius-server host 1.1.1.2 acct-port 1550 auth-port 1560 test username user1 idle-time 30 key abc1234

Switch(config)#

dot1x critical eapol

Switch(config)#

dot1x critical recovery delay 2000

Switch(config)#

interface gigabitethernet 1/0/1

Switch(config-if)#

dot1x critical

Switch(config-if)#

dot1x critical recovery action reinitialize

Switch(config-if)#

dot1x critical vlan 20

Switch(config-if)#

end

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Configuring 802.1x Authentication with WoL

Configuring 802.1x Authentication with WoL

Beginning in privileged EXEC mode, follow these steps to enable 802.1x authentication with WoL. This procedure is optional.

SUMMARY STEPS



3. authentication control-direction {both | in}

4. end



DETAILED STEPS

Step 1

Step 2

Step 3

Step 4


Purpose


Example:

Switch#



Example:

Switch(config)#



authentication control-direction {both | in}

Example:

Switch(config-if)#

authentication control-direction both

Enables 802.1x authentication with WoL on the port, and use these keywords to configure the port as bidirectional or unidirectional.

• both—Sets the port as bidirectional. The port cannot receive packets from or send packets to the host. By default, the port is bidirectional.

• in—Sets the port as unidirectional. The port can send packets to the host but cannot receive packets from the host.


end

Example:

Switch(config-if)#

end

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Configuring MAC Authentication Bypass

Step 5

Step 6



Example:

Switch#



Example:

Switch#


Configuring MAC Authentication Bypass

Beginning in privileged EXEC mode, follow these steps to enable MAC authentication bypass. This procedure is optional.

SUMMARY STEPS




4. mab [eap]

5. end

DETAILED STEPS

Step 1

Step 2


Purpose


Example:

Switch#



Example:

Switch(config)#



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Configuring 802.1x User Distribution

Step 3

Step 4

Step 5

Command or Action authentication port-control auto

Purpose


Example:

Switch(config-if)#


mab [eap]

Enables MAC authentication bypass.

(Optional) Use the eap keyword to configure the switch to use EAP for authorization.

Example:

Switch(config-if)#

mab end


Example:

Switch(config-if)#

end


Beginning in privileged EXEC mode, follow these steps to configure a VLAN group and to map a VLAN to it:

SUMMARY STEPS


2. vlan group vlan-group-name vlan-list vlan-list

3. end

4. no vlan group vlan-group-name vlan-list vlan-list

DETAILED STEPS

Step 1


Example:

Switch#


Purpose


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73



Step 2

Step 3

Step 4


vlan group vlan-group-name vlan-list vlan-list

Example:

Switch(config)#

vlan group eng-dept vlan-list 10

Purpose

Configures a VLAN group, and maps a single VLAN or a range of VLANs to it.

end


Example:

Switch(config)#

end

no vlan group vlan-group-name vlan-list vlan-list

Example:

Switch(config)#

no vlan group eng-dept vlan-list

10

Clears the VLAN group configuration or elements of the VLAN group configuration.

Example of Configuring VLAN Groups

This example shows how to configure the VLAN groups, to map the VLANs to the groups, to and verify the

VLAN group configurations and mapping to the specified VLANs:

Switch(config)#


Switch(config)#

show vlan group group-name eng-dept

Group Name

------------eng-dept

Vlans Mapped

--------------

10

Switch(config)#

show dot1x vlan-group all

Group Name

-------------

Vlans Mapped

-------------eng-dept hr-dept

10

20

This example shows how to add a VLAN to an existing VLAN group and to verify that the VLAN was added:

Switch(config)#


Switch(config)#

show vlan group eng-dept

Group Name

------------eng-dept

Vlans Mapped

--------------

10,30

This example shows how to remove a VLAN from a VLAN group:

Switch#

no vlan group eng-dept vlan-list 10

This example shows that when all the VLANs are cleared from a VLAN group, the VLAN group is cleared:

Switch(config)#

no vlan group eng-dept vlan-list 30

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Configuring NAC Layer 2 802.1x Validation

Vlan 30 is successfully cleared from vlan group eng-dept.

Switch(config)#

show vlan group group-name eng-dept

This example shows how to clear all the VLAN groups:

Switch(config)#

no vlan group end-dept vlan-list all

Switch(config)#

show vlan-group all

For more information about these commands, see the Cisco IOS Security Command Reference.


You can configure NAC Layer 2 802.1x validation, which is also referred to as 802.1x authentication with a

RADIUS server.

Beginning in privileged EXEC mode, follow these steps to configure NAC Layer 2 802.1x validation. The procedure is optional.

SUMMARY STEPS




4. authentication event no-response action authorize vlan vlan-id


6. authentication timer reauthenticate

7. end



DETAILED STEPS

Step 1

Step 2


Purpose


Example:

Switch#



Example:

Switch(config)#



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75



Step 3

Step 4

Step 5

Step 6

Step 7

Step 8

Step 9


Purpose

Sets the port to access mode only if you configured the

RADIUS server.

Example:

Switch(config-if)#

switchport mode access authentication event no-response action authorize vlan

vlan-id

Specifies an active VLAN as an 802.1x guest VLAN. The range is 1 to 4094.

Example:


VLAN (routed port), an RSPAN VLAN, or a voice VLAN as an 802.1x guest VLAN.

Switch(config-if)#

authentication event no-response action authorize vlan 8 authentication periodic

Enables periodic re-authentication of the client, which is disabled by default.

Example:

Switch(config-if)#

authentication periodic authentication timer reauthenticate

Example:

Switch(config-if)#

authentication timer reauthenticate end

Sets re-authentication attempt for the client (set to one hour).

This command affects the behavior of the switch only if periodic re-authentication is enabled.


Example:

Switch(config-if)#

end


Example:

Switch#



Example:

Switch#


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Configuring Limiting Login for Users

Configuring Limiting Login for Users

SUMMARY STEPS

1. enable



4. aaa authentication login default local

5. aaa authentication rejected n in m ban x

6. end

7. show aaa local user blocked

8. clear aaa local user blocked username username

DETAILED STEPS

Step 1

Step 2

Step 3

Step 4

Step 5


Purpose

Enables privileged EXEC mode.

• Enter your password if prompted.

Example:

Device> enable



Example:

Device# configure terminal

aaa new-model

Enables the authentication, authorization, and accounting (AAA) access control model.

Example:

Device(config)# aaa new-model

aaa authentication login default local

Sets the authentication, authorization, and accounting (AAA) authentication by using the default authentication methods.

Example:

Device(config)# aaa authentication login default local

aaa authentication rejected n in m ban x

Example:

Device(config)# aaa authentication rejected

3 in 20 ban 300

Configures the time period for which an user is blocked, if the user fails to successfully login within the specified time and login attempts.

• n—Specifies the number of times a user can try to login.

• m—Specifies the number of seconds within which an user can try to login.

• x—Specifies the time period an user is banned if the user fails to successfully login.

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Configuring an Authenticator Switch with NEAT

Step 6

Step 7

Step 8


Purpose

Exits global configuration mode and returns to privileged EXEC mode.

Example:

Device(config)# end

show aaa local user blocked

Displays the list of local users who were blocked.

Example:

Device# show aaa local user blocked

clear aaa local user blocked username username Clears the information about the blocked local user.

Example:

Device# clear aaa local user blocked username user1

The following is sample output from the show aaa local user blocked command:

Device#

show aaa local user blocked

Local-user State user1 Watched (till 11:34:42 IST Feb 5 2015)


Configuring this feature requires that one switch outside a wiring closet is configured as a supplicant and is connected to an authenticator switch.

Note

The cisco-av-pairs must be configured as device-traffic-class=switch on the ACS, which sets the interface as a trunk after the supplicant is successfully authenticated.

Beginning in privileged EXEC mode, follow these steps to configure a switch as an authenticator:

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SUMMARY STEPS


2. cisp enable




6. dot1x pae authenticator

7. spanning-tree portfast

8. end

9. show running-config interface interface-id


DETAILED STEPS

Step 1

Step 2

Step 3

Step 4

Step 5


Purpose


Example:

Switch#

configure terminal cisp enable

Enables CISP.

Example:

Switch(config)#

cisp enable


Example:

Switch(config)#


Sets the port mode to access.

Example:

Switch(config-if)#


Example:

Switch(config-if)#


Sets the port-authentication mode to auto.

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Configuring a Supplicant Switch with NEAT

Step 6

Step 7

Step 8

Step 9

Step 10

Command or Action dot1x pae authenticator

Example:

Switch(config-if)#

dot1x pae authenticator spanning-tree portfast

Example:

Switch(config-if)#

spanning-tree portfast trunk end

Example:

Switch(config-if)#

end

show running-config interface interface-id

Example:

Switch#

show running-config interface gigabitethernet2/0/1 copy running-config startup-config

Example:

Switch#


Purpose

Configures the interface as a port access entity

(PAE) authenticator.

Enables Port Fast on an access port connected to a single workstation or server..


Verifies your configuration.



Beginning in privileged EXEC mode, follow these steps to configure a switch as a supplicant:

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SUMMARY STEPS


2. cisp enable

3. dot1x credentials profile

4. username suppswitch

5. password password

6. dot1x supplicant force-multicast


8. switchport trunk encapsulation dot1q

9. switchport mode trunk

10. dot1x pae supplicant

11. dot1x credentials profile-name

12. end



15. Configuring NEAT with Auto Smartports Macros

DETAILED STEPS

Step 1

Step 2

Step 3

Step 4


Example:

Switch#

configure terminal cisp enable

Example:

Switch(config)#

cisp enable

dot1x credentials profile

Example:

Switch(config)#

dot1x credentials test

username suppswitch

Example:

Switch(config)#

username suppswitch

Purpose


Enables CISP.

Creates 802.1x credentials profile. This must be attached to the port that is configured as supplicant.

Creates a username.

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81



Step 5

Step 6

Step 7

Step 8

Step 9

Step 10

Step 11

Step 12


password password

Example:

Switch(config-if)#

switchport trunk encapsulation dot1q switchport mode trunk

Purpose

Creates a password for the new username.

Example:

Switch(config)#

password myswitch dot1x supplicant force-multicast

Forces the switch to send only multicast EAPOL packets when it receives either unicast or multicast packets.

Example:

Switch(config)#

dot1x supplicant force-multicast

This also allows NEAT to work on the supplicant switch in all host modes.


Example:

Switch(config)#



switchport trunk encapsulation dot1q

Sets the port to trunk mode.

Configures the interface as a VLAN trunk port.

Example:

Switch(config-if)#

switchport mode trunk dot1x pae supplicant

Configures the interface as a port access entity (PAE) supplicant.

Example:

Switch(config-if)#

dot1x pae supplicant

dot1x credentials profile-name Attaches the 802.1x credentials profile to the interface.

Example:

Switch(config-if)#

dot1x credentials test end


Example:

Switch(config-if)#

end

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Configuring 802.1x Authentication with Downloadable ACLs and Redirect URLs

Step 13

Step 14

Step 15


show running-config interface interface-id

Example:

Switch#


Example:

Switch#


Configuring NEAT with Auto Smartports Macros

Purpose

Verifies your configuration.


You can also use an Auto Smartports user-defined macro instead of the switch VSA to configure the authenticator switch. For more information, see the Auto Smartports

Configuration Guide for this release.


In addition to configuring 802.1x authentication on the switch, you need to configure the ACS. For more information, see the Configuration Guide for Cisco Secure ACS 4.2: http://www.cisco.com/en/US/docs/net_mgmt/cisco_secure_access_control_server_for_windows/4.2/configuration/guide/acs_config.pdf

Note

You must configure a downloadable ACL on the ACS before downloading it to the switch.

After authentication on the port, you can use the show ip access-list privileged EXEC command to display the downloaded ACLs on the port.

Configuring Downloadable ACLs

The policies take effect after client authentication and the client IP address addition to the IP device tracking table. The switch then applies the downloadable ACL to the port.

Beginning in privileged EXEC mode:

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83



SUMMARY STEPS


2. ip device tracking


4. aaa authorization network default local group radius

5. radius-server vsa send authentication


7. ip access-group acl-id in



DETAILED STEPS

Step 1

Step 2

Step 3

Step 4

Step 5


Purpose


Example:

Switch#

configure terminal ip device tracking

Sets the ip device tracking table.

Example:

Switch(config)#

ip device tracking aaa new-model

Enables AAA.

Example:

Switch(config)#

aaa new-model aaa authorization network default local group radius

Example:

Switch(config)#

aaa authorization network default local group radius

Sets the authorization method to local. To remove the authorization method, use the no aaa authorization

network default local group radius command.

radius-server vsa send authentication

Configures the radius vsa send authentication.

Example:

Switch(config)#


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Step 6

Step 7

Step 8

Step 9



Purpose


Example:

Switch(config)#


ip access-group acl-id in

Example:

Switch(config-if)#

ip access-group default_acl in

Configures the default ACL on the port in the input direction.

Note

The acl-id is an access list name or number.

show running-config interface interface-id Verifies your configuration.

Example:

Switch(config-if)#



Example:

Switch#


Configuring a Downloadable Policy

Beginning in privileged EXEC mode:

SUMMARY STEPS


2. access-list access-list-number { deny | permit } { hostname | any | host } log


4. ip access-group acl-id in

5. exit


7. aaa authorization network default group radius

8. ip device tracking

9. ip device tracking probe [count | interval | use-svi]

10. radius-server vsa send authentication

11. end

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85



DETAILED STEPS

Step 1

Step 2

Step 3

Step 4

Step 5


Purpose


Example:

Switch#


access-list access-list-number { deny | permit

} { hostname | any | host } log

Defines the default port ACL.

The access-list-number is a decimal number from 1 to 99 or 1300 to

1999.

Example:

Switch(config)#

access-list 1 deny any log

Enter deny or permit to specify whether to deny or permit access if conditions are matched.

The source is the source address of the network or host that sends a packet, such as this:

• hostname: The 32-bit quantity in dotted-decimal format.

• any: The keyword any as an abbreviation for source and source-wildcard value of 0.0.0.0 255.255.255.255. You do not need to enter a source-wildcard value.

• host: The keyword host as an abbreviation for source and source-wildcard of source 0.0.0.0.


(Optional) Applies the source-wildcard wildcard bits to the source.

(Optional) Enters log to cause an informational logging message about the packet that matches the entry to be sent to the console.

Enters interface configuration mode.

Example:

Switch(config)#


ip access-group acl-id in Configures the default ACL on the port in the input direction.

Note

The acl-id is an access list name or number.

Example:

Switch(config-if)#

ip access-group default_acl in exit

Returns to global configuration mode.

Example:

Switch(config-if)#

exit

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Step 6

Step 7

Step 8

Step 9

Step 10

Step 11

Command or Action aaa new-model

Purpose

Enables AAA.

Example:

Switch(config)#

aaa new-model aaa authorization network default group radius

Sets the authorization method to local. To remove the authorization method, use the no aaa authorization network default group radius command.

Example:

Switch(config)#

aaa authorization network default group radius ip device tracking

Example:

Switch(config)#

ip device tracking

Enables the IP device tracking table.

To disable the IP device tracking table, use the no ip device tracking global configuration commands.

ip device tracking probe [count | interval |

use-svi]

(Optional) Configures the IP device tracking table:

• count count—Sets the number of times that the switch sends the

ARP probe. The range is from 1 to 5. The default is 3.

Example:

Switch(config)#

ip device tracking probe count

• interval interval—Sets the number of seconds that the switch waits for a response before resending the ARP probe. The range is from 30 to 300 seconds. The default is 30 seconds.

• use-svi—Uses the switch virtual interface (SVI) IP address as source of ARP probes.


Example:

Switch(config)#


Configures the network access server to recognize and use vendor-specific attributes.

Note

The downloadable ACL must be operational.

end


Example:

Switch(config)#

end

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87


Configuring VLAN ID-based MAC Authentication

Configuring VLAN ID-based MAC Authentication

Beginning in privileged EXEC mode, follow these steps:

SUMMARY STEPS


2. mab request format attribute 32 vlan access-vlan


DETAILED STEPS

Step 1

Step 2

Step 3


Purpose


Example:

Switch#

configure terminal mab request format attribute 32 vlan access-vlan

Enables VLAN ID-based MAC authentication.

Example:

Switch(config)#

mab request format attribute 32 vlan access-vlan copy running-config startup-config


Example:

Switch#


Configuring Flexible Authentication Ordering

The examples used in the instructions below changes the order of Flexible Authentication Ordering so that

MAB is attempted before IEEE 802.1X authentication (dot1x). MAB is configured as the first authentication method, so MAB will have priority over all other authentication methods.

Note

Before changing the default order and priority of these authentication methods, however, you should understand the potential consequences of those changes. See http://www.cisco.com/en/US/prod/collateral/ iosswrel/ps6537/ps6586/ps6638/application_note_c27-573287_ps6638_Products_White_Paper.html

for details.

Beginning in privileged EXEC mode, follow these steps:

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Configuring Flexible Authentication Ordering

SUMMARY STEPS




4. authentication order [ dot1x | mab ] | {webauth}

5. authentication priority [ dot1x | mab ] | {webauth}

6. end

DETAILED STEPS

Step 1

Step 2

Step 3

Step 4

Step 5

Step 6


Purpose


Example:

Switch#



Example:

Switch(config-if)#

authentication priority mab dot1x end


Example:

Switch(config)#

interface gigabitethernet 1/0/1 switchport mode access

Sets the port to access mode only if you previously configured the RADIUS server.

Example:

Switch(config-if)#


authentication order [ dot1x | mab ] | {webauth}

Example:

Switch(config-if)#

authentication order mab dot1x

(Optional) Sets the order of authentication methods used on a port.

authentication priority [ dot1x | mab ] | {webauth} (Optional) Adds an authentication method to the port-priority list.


Example:

Switch(config-if)#

end

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89


Configuring Open1x

Related Topics

Flexible Authentication Ordering, on page 30


Beginning in privileged EXEC mode, follow these steps to enable manual control of the port authorization state:

SUMMARY STEPS




4. authentication control-direction {both | in}

5. authentication fallback name

6. authentication host-mode [multi-auth | multi-domain | multi-host | single-host]

7. authentication open

8. authentication order [ dot1x | mab ] | {webauth}


10. authentication port-control {auto | force-authorized | force-un authorized}

11. end

DETAILED STEPS

Step 1

Step 2

Step 3


Example:

Switch#



Purpose



Example:

Switch(config)#

interface gigabitethernet 1/0/1 switchport mode access

Example:

Switch(config-if)#


Sets the port to access mode only if you configured the RADIUS server.

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Step 4

Step 5

Step 6

Step 7

Step 8

Step 9

Step 10


authentication control-direction {both | in}

Example:

Switch(config-if)#

authentication control-direction both

Purpose

(Optional) Configures the port control as unidirectional or bidirectional.

authentication fallback name

Example:

Switch(config-if)#

authentication fallback profile1

(Optional) Configures a port to use web authentication as a fallback method for clients that do not support

802.1x authentication.

authentication host-mode [multi-auth | multi-domain |

multi-host | single-host]

(Optional) Sets the authorization manager mode on a port.

Example:

Switch(config-if)#

authentication host-mode multi-auth authentication open

(Optional) Enables or disable open access on a port.

Example:

Switch(config-if)#

authentication open

authentication order [ dot1x | mab ] | {webauth} (Optional) Sets the order of authentication methods used on a port.

Example:

Switch(config-if)#

authentication order dot1x webauth authentication periodic

(Optional) Enables or disable reauthentication on a port.

Example:

Switch(config-if)#

authentication periodic

authentication port-control {auto | force-authorized |

force-un authorized}

(Optional) Enables manual control of the port authorization state.

Example:

Switch(config-if)#


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Disabling 802.1x Authentication on the Port

Step 11


Example:

Switch(config-if)#

end

Purpose


Related Topics

Open1x Authentication, on page 31

Disabling 802.1x Authentication on the Port

You can disable 802.1x authentication on the port by using the no dot1x pae interface configuration command.

Beginning in privileged EXEC mode, follow these steps to disable 802.1x authentication on the port. This procedure is optional.

SUMMARY STEPS




4. no dot1x pae authenticator

5. end

DETAILED STEPS

Step 1

Step 2


Example:

Switch#



Example:

Switch(config)#


Purpose



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Resetting the 802.1x Authentication Configuration to the Default Values

Step 3

Step 4

Step 5


Purpose

(Optional) Sets the port to access mode only if you configured the RADIUS server.

Example:

Switch(config-if)#

switchport mode access no dot1x pae authenticator

Disables 802.1x authentication on the port.

Example:

Switch(config-if)#

no dot1x pae authenticator end


Example:

Switch(config-if)#

end

Resetting the 802.1x Authentication Configuration to the Default Values

Beginning in privileged EXEC mode, follow these steps to reset the 802.1x authentication configuration to the default values. This procedure is optional.

SUMMARY STEPS



3. dot1x default

4. end

DETAILED STEPS

Step 1


Example:

Switch#


Purpose


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Monitoring 802.1x Statistics and Status

Step 2

Step 3

Step 4



Example:

Switch(config)#


Purpose

Enters interface configuration mode, and specify the port to be configured.

dot1x default

Resets the 802.1x parameters to the default values.

Example:

Switch(config-if)#

dot1x default end


Example:

Switch(config-if)#

end

Monitoring 802.1x Statistics and Status

Table 5: Privileged EXEC show Commands

Command show dot1x all statistics

show dot1x interface interface-id statistics

show dot1x all [count | details | statistics |

summary]

show dot1x interface interface-id

Purpose

Displays 802.1x statistics for all ports

Displays 802.1x statistics for a specific port

Displays the 802.1x administrative and operational status for a switch

Displays the 802.1x administrative and operational status for a specific port

Table 6: Global Configuration Commands

Command no dot1x logging verbose

Purpose

Filters verbose 802.1x authentication messages

(beginning with Cisco IOS Release 12.2(55)SE)

For detailed information about the fields in these displays, see the command reference for this release.

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Additional References for IEEE 802.1x Port-Based Authentication

Additional References for IEEE 802.1x Port-Based Authentication

Related Documents

Related Topic

Configuring Identity Control policies and Identity

Service templates for Session Aware networking.

Configuring RADIUS, TACACS+, Secure Shell,

802.1X and AAA.

Document Title

Session Aware Networking Configuration Guide,

Cisco IOS XE Release 3SE (Catalyst 3850 Switches) http://www.cisco.com/en/US/docs/ios-xml/ios/san/ configuration/xe-3se/3850/san-xe-3se-3850-book.html

Securing User Services Configuration Guide Library,

Cisco IOS XE Release 3SE (Catalyst 3850 Switches) http://www.cisco.com/en/US/docs/ios-xml/ios/ security/config_library/xe-3se/3850/ secuser-xe-3se-3850-library.html

Error Message Decoder

Description

To help you research and resolve system error messages in this release, use the Error Message

Decoder tool.

Link

https://www.cisco.com/cgi-bin/Support/Errordecoder/ index.cgi

MIBs

MIB

All supported MIBs for this release.

MIBs Link

To locate and download MIBs for selected platforms,

Cisco IOS releases, and feature sets, use Cisco MIB

Locator found at the following URL: http://www.cisco.com/go/mibs

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Feature Information for 802.1x Port-Based Authentication

Technical Assistance

Description Link

The Cisco Support website provides extensive online resources, including documentation and tools for troubleshooting and resolving technical issues with

Cisco products and technologies.

http://www.cisco.com/support

To receive security and technical information about your products, you can subscribe to various services, such as the Product Alert Tool (accessed from Field

Notices), the Cisco Technical Services Newsletter, and Really Simple Syndication (RSS) Feeds.

Access to most tools on the Cisco Support website requires a Cisco.com user ID and password.

Feature Information for 802.1x Port-Based Authentication

Release

Cisco IOS XE 3.2SE

Feature Information

This feature was introduced.

Supports the use of same authorization methods on all the Catalyst switches in a network.

Supports filtering verbose system messages from the authentication manager.

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