Grandstream Networks, Inc.
802.1x Authentication Guide
Table of Content
SUPPORTED DEVICES ................................................................................................. 4
INTRODUCTION ............................................................................................................. 5
802.1X AUTHENTICATION PROCESS.......................................................................... 6
802.1x Elements........................................................................................................................................ 6
Authentication Process ............................................................................................................................. 6
Authentication Flowchart ........................................................................................................................... 7
EAP Methods for 802.1x Authentication ................................................................................................... 8
802.1X AUTHENTICATION CONFIGURATION ............................................................. 9
Via Web User Interface ............................................................................................................................. 9
Via Phone Keypad................................................................................................................................... 10
802.1X AUTHENTICATION FLOW............................................................................... 12
Authentication Process Using EAP-MD5 Protocol .................................................................................. 12
Authentication Process .................................................................................................................. 12
Flow Example ................................................................................................................................. 13
Authentication Process Using EAP-TLS Protocol ................................................................................... 13
Authentication Process .................................................................................................................. 13
Flow Example ................................................................................................................................. 15
Authentication Process Using EAP-PEAP (MSCHAPv2) Protocol ......................................................... 15
Authentication Process .................................................................................................................. 15
Flow Example ................................................................................................................................. 17
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802.1x Authentication Guide
Table of figures
Figure 1: 802.1x Authentication Process ...................................................................................................... 6
Figure 2: 802.1x Authentication Flowchart .................................................................................................... 7
Figure 3: 802.1x MD5 .................................................................................................................................... 9
Figure 4: 802.1x TLS................................................................................................................................... 10
Figure 5: 802.1x PEAP................................................................................................................................ 10
Figure 6: 802.1x mode (EAP-MD5) ............................................................................................................. 11
Figure 7: 802.1x mode (EAP-TLS) .............................................................................................................. 11
Figure 8: 802.1x mode (EAP-PEAP) ........................................................................................................... 11
Figure 9: 802.1x Authentication Using MD5 ............................................................................................... 12
Figure 10: EAP MD5 Challenge .................................................................................................................. 13
Figure 11: 802.1x Authentication Using TLS .............................................................................................. 14
Figure 12: EAP TLS Challenge ................................................................................................................... 15
Figure 13: 802.1x Authentication Using PEAPv0/MSCHAPv2 ................................................................... 16
Figure 14: EAP PEAP Challenge ................................................................................................................ 18
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802.1x Authentication Guide
SUPPORTED DEVICES
Following table shows Grandstream products supporting 802.1x feature:
Model
Supported
Firmware
Basic IP Phones
GXP16XX Series
GXP1610/1615
Yes
1.0.3.28 or higher
GXP1620/1625
Yes
1.0.3.28 or higher
GXP1628
Yes
1.0.3.28 or higher
GXP1630
Yes
1.0.3.28 or higher
Mid-Range IP Phones
GXP17XX Series
GXP1760
Yes
1.0.0.37 or higher
GXP1780/1782
Yes
1.0.0.37 or higher
High End IP Phones
GXP21XX Series
GXP2130/2140/2160
Yes
1.0.7.25 or higher
GXP2135/2170
Yes
1.0.7.25 or higher
IP Video Phones for Android
GXV32XX Series
GXV3240
Yes
1.0.3.92 or higher
GXV3275
Yes
1.0.3.92 or higher
Analog VoIP Gateways
GXW42XX Series
GXW4216
Yes
1.0.5.16 or higher
GXW4224
Yes
1.0.5.16 or higher
GXW4232
Yes
1.0.5.16 or higher
GXW4248
Yes
1.0.5.16 or higher
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802.1x Authentication Guide
INTRODUCTION
IEEE 802.1x is a standard for port-based Network Access Control (PNAC), designed to provide an
authentication mechanism for network devices to connect to LAN or WAN. The IEEE 802.1x protocol
includes the encapsulation of the Extensible Authentication Protocol (EAP) over LAN (known as “EAPOL”
or “EAP over LAN”) for messages exchange during the authentication process.
802.1x is implemented to accommodate the following:
•
Authentication based on Network Access Identifier and credentials.
•
Centralized authentication, authorization and accounting.
•
Public Network Security.
•
Distribution of dynamic encryption keys.
This guide will outline the use and configuration of 802.1x authentication on Grandstream IP phones.
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802.1x Authentication Guide
802.1X AUTHENTICATION PROCESS
802.1x Elements
The main elements interacting in 802.1x process are:
•
Supplicant: PC, Laptop, IP phones and any other device aiming to connect to the network.
•
Authenticator: Network switches/Wireless access points providing first connection level to
supplicants.
•
Authentication server: Server or device (Radius server, AD etc…) that can hold authentication
credentials for all users and verify provided information exchanged by end points during
authentication process.
Authentication Process
Please refer to following process describing how IEEE 802.1x operates:
Figure 1: 802.1x Authentication Process
1. The client/supplicant sends an EAP-start message and a series of messages are exchanged to
authenticate the client.
2. The access point forwards the EAP-request identity message.
3. The client sends an EAP-response packet that contains his identity to the authentication server.
4. The server uses a specific authentication algorithm to verify the client's identity.
5. The authentication server sends either an accept message or a reject message to the access point.
6. The access point sends an EAP-success packet or reject packet to the client.
7. When authentication server accepts the client, the access point transits the client's port to an
authorized state and forwards additional traffic.
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802.1x Authentication Guide
Additional information:
a) All messages between supplicant and authenticator are delivered in EAPOL (Extensible
Authentication Protocol Over LAN) form.
b) Authenticator converts messages to RADIUS messages and send them to RADIUS server
(Authentication Server)
c) Authentication Server negotiates the type of EAP authentication that is acceptable to both the
supplicant and itself and starts communicating with the supplicant via EAP messages to carry out
the authentication process. Some authenticators may not support all types of EAP and hence would
act as an EAP pass through where the supplicants directly communicate with Authentication
Servers to complete the authentication process.
Note: Before the authentication happens, the authenticator sets the network port to the Uncontrolled
State where only EAP / EAPOL messages are allowed to pass through between the supplicant and the
authentication server. All other traffic remains blocked from that network port. But after the authentication,
the network port is set to Controlled/Authorized State to grant network access according to the NAC
policies.
Authentication Flowchart
Please refer to following diagram describing and summarizing an implementation of 802.1x authentication
process:
Figure 2: 802.1x Authentication Flowchart
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802.1x Authentication Guide
EAP Methods for 802.1x Authentication
The following are the main types of EAP protocol for the 802.1x authentication supported:
•
EAP-MD5 (EAP-Message Digest 5): Basic authentication method using Username/Password
combination to verify authentication credentials and offering basic protection for the messages
exchanged. This type offers lowest security level and can be used in wired networks only requiring
basic security.
•
EAP-TLS (EAP-Transport Level Security): Client and Server authentication need to have preinstalled certificates to be authenticated, since those certificates are required and TLS tunnel is
created between the authentication server and client. This method is more secure and can be used
for wired and wireless networks.
•
EAP-PEAPv0/MSCHAPv2: The most common method form of PEAP; MSCHAP (Microsoft
Challenge Handshake Authentication Protocol) allows authentication to databases supporting MSCHAPv2 format, including Microsoft NT and Microsoft Active Directory and using a CA certificate
at each client to authenticate with the server. It’s a mutual authentication method that supports
password-based user or computer authentication. During the authentication process, both the
server and client must prove that they have knowledge of the user's password in order for
authentication to succeed.
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802.1x Authentication Guide
802.1X AUTHENTICATION CONFIGURATION
The configuration can be done either using the WebGUI or via phone keypad.
In this guide, we will work with GXV32xx series as example to configure the 802.1x authentication.
Via Web User Interface
To enable and configure 802.1x authentication using the web user interface on GXV32xx, please refer to
following steps:
1. Access to web GUI of your device.
2. Navigate to Maintenance  Network Settings  802.1x Mode.
3. Choose from drop down list the 802.1x method desired (EAP_MD5, EAP_TLS or EAP-PEAP)
•
If EAP-MD5 is selected:
a. Enter the username in 802.1x Identity field for authentication.
b. Enter the password in 802.1x Secret field for authentication.
Figure 3: 802.1x MD5
•
If EAP-TLS is selected:
a. Enter the username in 802.1x Identity field for authentication.
b. Enter the password in 802.1x Private Key Password field for authentication.
c.
Click Upload button to browse and load 802.1x CA Certificate (*.pem, *.cer, *.crt or *.der)
from your local system.
d. Click Upload button to browse and load the 802.1x Client Certificate (*.pem, or *.cer)
from your local system.
e. Click Upload button to browse and load the 802.1x Client Certificate (*.pem, or *.cer)
from your local system.
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802.1x Authentication Guide
Figure 4: 802.1x TLS
•
If EAP-PEAP is selected:
a. Enter the username in 802.1x Identity field for authentication.
b. Enter the password in 802.1x Secret field for authentication.
c.
Click Upload button to browse and load 802.1x CA Certificate (*.pem, *.cer, *.crt or *.der)
from your local system.
Figure 5: 802.1x PEAP
4. Press Save and Apply buttons and reboot your device to apply the new settings.
Via Phone Keypad
To enable and configure the 802.1x authentication using the keypad menu on GXV32xx, please refer to
following steps:
1. Press Menu button and navigate to Settings.
2. Access to Wireless & Network settings and navigate to Additional network settings
3. Access to 802.1x mode and select the method desired from the drop-down list.
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802.1x Authentication Guide
•
If EAP-MD5 is selected:
a. Enter the username in Identity field for authentication.
b. Enter the password in MD5 Password field for
authentication.
Figure 6: 802.1x mode (EAP-MD5)
•
If EAP-TLS is selected:
a. Enter the username in 802.1x Identity field for
authentication.
b. Enter the password in 802.1x Private Key Password
field for authentication.
c.
Click Upload button to browse and load 802.1x CA
Certificate (*.pem, *.cer, *.crt or *.der) from your local
system.
d. Click Upload button to browse and load the 802.1x Client
Certificate (*.pem, or *.cer) from your local system.
e. Click Upload button to browse and load the 802.1x Client
Figure 7: 802.1x mode (EAP-TLS)
Certificate (*.pem, or *.cer) from your local system.
•
If EAP-PEAP is selected:
a. Enter the username in 802.1x Identity field for
authentication.
b. Enter
the
password
in
802.1x
Secret
field
for
authentication.
c.
Click Upload button to browse and load 802.1x CA
Certificate (*.pem, *.cer, *.crt or *.der) from your local
system
Figure 8: 802.1x mode (EAP-PEAP)
4. Press OK for saving and reboot your device to apply the new settings.
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802.1x Authentication Guide
802.1X AUTHENTICATION FLOW
Once 802.1x settings are configured on the phone either via webGUI or via phone Keypad and device
rebooted. Authentication process is divided into two stages:
Prior to Authentication
The only messages that will be accepted from the client are the EAP messages, which will be forwarded to
the authentication server. The authenticator will block access to the network for the phone, it will try to
establish a security negotiation with the IP phone and create an 802.1X session. The IP phone provides its
authentication information for the authenticator, then the authenticator forwards the information to the
authentication server.
Authentication Process
After 802.1x client is powered on, it will transmit the EAP message to the authenticator. It will forward then
the client’s request to the authentication server without changing its contents. The server will verify the user
credentials and transmit back its response to the authenticator, which will determine whether the port
remains in blocked mode or will grant access to the client, if the server response is “Access granted” then
client port state will have access to the network. If the authentication fails, the authenticator port will remain
blocked, and in some cases the port will be disabled (depends on vendor implementation).
Authentication Process Using EAP-MD5 Protocol
Authentication Process
The following figure shows a successful 802.1x authentication process using EAP-MD5 protocol (RADIUS
is used as authentication server).
Figure 9: 802.1x Authentication Using MD5
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802.1x Authentication Guide
1. The client starts by sending an “EAPOL-Start” packet to the switch.
2. The switch reply to the client with an “EAP-Request/Identity” packet.
3. The client sends back an “EAP-Response/Identity” packet to the switch.
4. The switch strips the Ethernet header and encapsulates the remaining EAP frame in the RADIUS
format, and then sends it to the RADIUS server.
5. The RADIUS server recognizes the packet as an EAP-MD5 type and sends back a Challenge
message to switch.
6. The switch strips the authentication server’s frame header, encapsulates the remaining EAP
frame into the EAPOL format, and sends it to the client.
7. The client responds to the Challenge message.
8. The switch passes the response to the RADIUS server.
9. The RADIUS server validates the authentication information and sends an authentication success
message.
10. The switch passes the successful message to the client.
Once the phone is authenticated successfully, the switch provides network access permissions. If the phone
does not provide proper identification, RADIUS server will reply with a rejection message. The switch relies
the message to the phone and blocks access to the LAN. When the phone is disabled or reset, it will send
an EAPOL-Logoff message, which prompts the switch to block access to the LAN Success message.
Flow Example
The following figure shows a trace of EAP-MD5 process.
Figure 10: EAP MD5 Challenge
Authentication Process Using EAP-TLS Protocol
Authentication Process
The following figure shows a successful 802.1x authentication process using EAP-MD5 protocol (RADIUS
is used as authentication server).
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802.1x Authentication Guide
Figure 11: 802.1x Authentication Using TLS
1. The phone sends an “EAPO-Start” packet to the switch.
2. The switch reply with an “EAP-Request/Identity” packet.
3. The phone sends back an "EAP-Response/Identity" packet to the switch.
4. The switch strips the Ethernet header and encapsulates the remaining EAP frame in the RADIUS
format, and then sends it to the server.
5. The authentication server recognizes the packet as an EAP-TLS type and sends an “EAP-Request”
packet with a TLS start message to the switch.
6. The switch strips the authentication server’s frame header, encapsulates the remaining EAP frame
in the EAPOL format, and then sends it to the phone.
7. The phone responds with an “EAP-Respond” packet containing a TLS client hello handshake
message to the switch. The client hello message includes the TLS version supported by the phone,
a session ID, a random number and a set of cipher suites.
8. The switch passes the response to the authentication server.
9. TLS handshake between the phone and RADIUS server (phone and server exchange key and
cipher).
10. The phone responds with an “EAP-Response” packet to the switch.
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802.1x Authentication Guide
11. The switch passes the response to the server.
12. The server responds with a success message indicating that the phone and the RADIUS server
have successfully authenticated each other.
13. The switch passes the message to the phone.
After the phone’s successful authentication, the switch provides network access permissions. If the phone
does not provide proper identification, the RADIUS server responds with a rejection message. The switch
relies the message to the phone and blocks access to the LAN. When the phone is disabled or reset, it will
send an EAPOL-Logoff message, which tell the switch to block access to the LAN.
Flow Example
Bellow trace example of EAP-TLS authentication.
Figure 12: EAP TLS Challenge
Authentication Process Using EAP-PEAP (MSCHAPv2) Protocol
Authentication Process
The following figure shows a successful 802.1x authentication process using EAP-PEAPv0/MSCHAPv2
protocol (RADIUS is used as authentication server).
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802.1x Authentication Guide
Figure 13: 802.1x Authentication Using PEAPv0/MSCHAPv2
1. The phone sends an “EAPO-Start” packet to the switch.
2. The switch reply with an “EAP-Request/Identity” packet.
3. The phone sends back an "EAP-Response/Identity" packet to the switch.
4. The switch strips the Ethernet header and encapsulates the remaining EAP frame in the RADIUS
format, and then sends it to the server.
5. The authentication server recognizes the packet as an EAP-TLS type and sends an “EAP-Request”
packet with a TLS start message to the switch.
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802.1x Authentication Guide
6. The switch strips the authentication server’s frame header, encapsulates the remaining EAP frame
in the EAPOL format, and then sends it to the phone.
7. The phone responds with an “EAP-Respond” packet containing a TLS client hello handshake
message to the switch. The client hello message includes the TLS version supported by the phone,
a session ID, a random number and a set of cipher suites.
8. The switch passes the response to the authentication server.
9. TLS handshake between the phone and RADIUS server (phone and server exchange key and
cipher).
10. The phone responds with an “EAP-Response” packet.
11. The switch passes the response to the server.
12. The RADIUS server sends an “EAP-Request/Identity” packet.
13. The switch relies the request to the phone.
14. The phone replies with an “EAP-Response/Identity” packet.
15. The switch passes the response to the RADIUS server.
16. The RADIUS server sends an “EAP-Request” packet that includes a MSCHAPv2 challenge
message.
17. The switch passes the request to the phone.
18. The phone sends back a challenge message to the switch.
19. The switch relies the message to the server.
20. The RADIUS server sends a success message indicating that the phone provided the proper
identity.
21. The switch relies the message to the phone.
22. The phone responds with an ACK message to the switch.
23. The switch relies the respond message to the server.
24. The RADIUS server sends a successful message to the switch.
25. The switch passes the message to the phone.
After the phone’s successful authentication, the switch provides network access permissions. If the phone
does not provide proper identification, the RADIUS server responds with a rejection message. The switch
relies the message to the phone and blocks access to the LAN. When the phone is disabled or reset, it will
send an EAPOL-Logoff message to block access to the LAN on the switch.
Flow Example
Below trace example of EAP-PEAPv0/MSCHAPv2 authentication.
Please note that the trace contains two phases, the first one is similar to the EAP TLS challenge, after the
“EAP-Response” in step 10, the server sends another “EAP-Request/Identity” protected by the TLS
ciphersuite negotiated in phase 1 to exchange the phone user and password.
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802.1x Authentication Guide
Figure 14: EAP PEAP Challenge
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802.1x Authentication Guide
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