CT5760 High Availability AP SSO Deployment Guide, Cisco IOS XE

CT5760 High Availability AP SSO Deployment Guide, Cisco IOS XE
CT5760 High Availability AP SSO Deployment
Guide, Cisco IOS XE Release 3.3
Last Updated: November, 2014
Release: CT 5760 High Availability AP SSO Deployment Guide, Cisco IOS XE Release 3.3
Introduction
This document introduces the Access Point Stateful Switch Over redundancy model for High
Availability (HA) with CT5760 controllers using the StackWise-480 technology. HA in Cisco 5700
Series Wireless Controller is enabled using Cisco StackWise-480 technology. This deployment guide
applies only to the Converged Access CT5760 Wireless LAN Controller. For more information on the
CT5760 please refer to CT5760 Controller Deployment Guide.
CT5760 Controller
CT5760 is an innovative UADP ASIC based wireless controller deployed as a centralized controller in
the next generation unified wireless architecture. CT5760 controllers are specifically designed to
function as Unified model central wireless controllers. They also support the newer Mobility
functionality with Converged Access switches in the wireless architecture.
Cisco Systems, Inc.
www.cisco.com
5760 Access Point Stateful Switch Over (AP SSO) Overview
Figure 1
Cisco WLC 5760
CT5760 is an extensible and high performing wireless controller, which can scale up to 1000 access
points and 12000 clients. The controller has 6 - 10 Gbps data ports.
As a component of the Cisco Unified Wireless Network, the CT5760 series works in conjunction with
Cisco Aironet access points, the Cisco Prime infrastructure, and the Cisco Mobility Services Engine to
support business-critical wireless data, voice, and video applications.
5760 Access Point Stateful Switch Over (AP SSO) Overview
IOS XE 3.3 SE release for Cisco 5700 Series Wireless Controller introduces 1:1 Active-Standby
redundancy model for HA with the CT5760 controllers using the StackWise-480 technology. HA in
Cisco 5700 Series Wireless Controller is enabled using Cisco StackWise-480 technology.
StackWise-480 identifies active and standby members in the stack as per the Cisco IOS Software SSO
technology. All the control plane activities are centralized and synchronized between the active and
standby units. The Active Controller centrally manages all the control and management communication.
The network control data traffic is transparently switched from the standby unit to the active unit for
centralized processing. The 12 ports of the CT5760 HA redundant pair can be connected to the
infrastructure network either through a single switch or two switches.
Bulk and Incremental configuration is synced between the two controllers at run-time and both
controllers share the same IP address on the management interface. The CAPWAP state of the Access
Points that are in Run State is also synched from the active WLC to the Hot-Standby WLC allowing the
Access Points to be state-fully switched over when the Active WLC fails. The APs do not go to the
Discovery state when Active WLC fails, and Standby WLC takes over as the Active WLC to serve the
network.
There is no preempt functionality with SSO meaning that when the previous Active WLC resumes
operation, it will not take back the role as an Active WLC but will negotiate its state with the current
Active WLC and transition to the Hot-Standby state. The Active and Standby election process is an
automated election process that occurs as part of the SSO StackWise technology and will be explained
later in the document.
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StackWise-480 Connectivity for HA
HA with AP SSO is supported in Cisco 5700 Series Wireless Controllers. IOS XE 3.3 release only
supports AP SSO i.e. APs will not disconnect and continue to be associated to the controller after a
switchover. However, all clients will be de-authenticated and forced to rejoin new the Active WLC
because Client SSO is not supported with this release.
StackWise-480 Connectivity for HA
A CT5760 HA Pair is a special case of a switch stack that can have up to two CT5760 controllers
connected through their StackWise-480 ports. The stack members work together as a unified system. A
third CT5760 cannot join the switch stack or HA pair. A switch stack always has one active controller
and one standby controller. If the active controller becomes unavailable, the standby assumes the role of
the active, and continues to the keep the stack operational. The active controller controls the operation
of the HA pair, and is the single point of stack-wide management. The term switch is loosely used in the
document to refer to the CT5760 WLC for this reason.
StackWise-480 has a stack bandwidth of 480 Gbps and uses SSO to provide resiliency within the HA
Pair. The Active CT5760 WLC creates and updates all the wireless information and constantly
synchronizes that information with the standby controller. If the active WLC fails, the standby WLC
assumes the role of the active WLC and continues to the keep the HA Pair operational. Access Points
continue to remain connected during an active-to-standby switchover.
The StackWise-480 Cable is shown below and is available in lengths of 50 cm, 1 m, and 3 m.
Figure 2
StackWise-480 Cable
Figure 3
Stack Cable Part Numbers
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StackWise-480 Connectivity for HA
Each CT5760 WLC has two Stack Ports and it is recommended to connect the Stack Cables in a full-ring
setup as shown below for stack cable redundancy.
Figure 4
CT5760 Controllers Connected in Full-ring Setup
The StackWise-480 cable needs to be plugged into the Stack Port as shown below with the Cisco Logo
facing upward.
Figure 5
Stack Cable Plugged into Stack Port on CT5760 WLC
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Verifying Stack Cable Connectivity
Note
Customers who buy AIR-CT5760-HA with 3.3 will also be given an option to buy stack cables.
Verifying Stack Cable Connectivity
The command show switch stack-ports summary can be used to verify the connectivity of the Stack
Cables.
Figure 6
show switch stack-ports summary Output
Verify that the:
•
Port Status is OK i.e. The cable is detected and connected neighbor is up.
•
Link OK is Yes i.e. The stack cable connected.
•
Link Active is Yes i.e. The neighbor is detected. The Port can send traffic over this link.
The table provides details on what the various fields refer to.
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Verifying Stack Cable Connectivity
Table 1
Description of show switch stack-ports summary Output
Parameter
Description
Switch#/Port#
Member number and its stack port number.
Stack Port Status
Status of the stack port.
•
Absent—No cable is detected on the stack
port.
•
Down—A cable is detected, but either no
connected neighbor is up or the stack port is
disabled.
•
OK—A cable is detected and the connected
neighbor is up.
Neighbor
Switch number of the active member at the other
end of the stack cable.
Cable Length
Valid lengths are 50 cm, 1 m, or 3 m. If the
CT5760 WLC cannot detect the cable length, the
value is no cable. The cable might not be
connected or the link might be unreliable.
Link OK
Whether the stack cable is connected and
functional. There may or may not be a neighbor
connected on the other end. The link partner is a
stack port on a neighbor switch.
Link Active
Sync OK
•
No—There is no stack cable connected to this
port or the stack cable is not functional.
•
Yes—There is a functional stack cable
connected to this port.
Whether a neighbor is connected on the other end
of the stack cable.
•
No—No neighbor is detected on the other
end. The port cannot send traffic over this
link.
•
Yes—A neighbor is detected on the other end.
The port can send traffic over this link.
Whether the link partner sends valid protocol
messages to the stack port.
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•
No—The link partner does not send valid
protocol messages to the stack port.
•
Yes—The link partner sends valid protocol
messages to the port.
Monitoring the HA Pair
Table 1
Description of show switch stack-ports summary Output
Parameter
Description
# Changes to LinkOK
The relative stability of the link. If a large number
of changes occur in a short period of time, link
flapping can occur.
In Loopback
Whether a stack cable is attached to a stack port
on the member.
•
No—At least one stack port on the member
has an attached stack cable.
•
Yes—None of the stack ports on the member
has an attached stack cable.
Monitoring the HA Pair
The command show switch displays summary information about the HA Pair, including the MAC
address, role, switch priority, and current state of each CT5760 WLC in the redundant HA pair.
Figure 7
show switch Output
By default, the Local MAC Address of the HA Pair is the MAC address of the current Active Controller.
When a switchover occurs, the MAC address changes to the MAC address of the new Active Controller.
However, the Persistent MAC Address feature can be used to set a time delay before the MAC address
changes.
Figure 8
•
MAC Persistency Feature Command
Enter the command without a value or with a value of 0 to continue using the MAC Address of the
current active controller indefinitely.
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Accessing Standby WLC Console
•
Enter a time-value from 1 to 60 minutes to configure the time period before the redundant unit MAC
Address changes to the new Active Controller. The MAC address of the previous active controller
is used until the configured time period expires.
Accessing Standby WLC Console
The active controller can be accessed through a console connection, Telnet, an SSH, or a Web Browser
by using the Management IP address. To access the IOS console of the standby WLC, use the session
standby ios privileged EXEC command from the active CT5760 after executing the following
commands from the config mode.
conf t
service internal
redundancy
main-cpu
standby console enable
end
session standby ios
The prompt on the Standby console is appended with “-stby” to reflect the Standby WLC console as
shown below.
Note
The standby access commands do not survive a reboot and need to be configured every time the WLC
reboots. The commands also do not show in "show run all”.
Figure 9
Standby Console and show switch for Standby WLC
The show switch command points to the current CT5760 WLC on the console using the (*) symbol
against the switch number as shown above.
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CT5760 WLC Active and Standby Election Process
CT5760 WLC Active and Standby Election Process
An active CT5760 WLC retains its role as an Active Controller unless one of the following events occur:
•
The CT5760 WLC HA pair is reset.
•
The active CT5760 WLC is removed from the HA pair.
•
The active CT5760 WLC is reset or powered off.
•
The active CT5760 WLC fails.
•
Powered-on standalone CT5760 WLC is merged with the current Active CT5760 WLC.
The active WLC CT5760 is elected or re-elected based on one of these factors and in the order listed
below:
Note
1.
The CT5760 that is currently the active CT5760.
2.
The CT5760 WLC with the highest stack member priority value.
We recommend assigning the highest priority value to the WLC 5760 you prefer to be the active
controller. This ensures that the controller is re-elected as active controller if a re-election occurs.
Setting the Switch Priority Value
switch stack-member-number priority new-priority-number
\\ Specifies the stack member number and the new priority for the stack member. The stack member
number range is 1 to 9. The priority value range is 1 to 15.
Example
5760# switch 2 priority 2
You can display the current priority value by using the show switch user EXEC command. The new
priority value takes effect immediately but does not affect the current Active Controller. The new priority
value helps determine which controller is elected as the new Active Controller when the current active
CT5760 WLC or HA redundant pair reloads.
3.
The CT5760 with the shortest start-up time.
4.
The CT5760 with the lowest MAC Address.
The ACTV LED on the switch can be used to identify the current Active Controller.
Best Practices for HA Pairing Process
•
Adding a powered-on CT5760 WLC (merging) to an existing Active Controller causes both WLCs
to reload and elect a new active controller from among themselves.
•
Make sure that the controller to be paired is powered down before connecting it to the existing
Active Controller by using Stack Cables. Once the Stack Cables are connected, power on the new
controller. The newly introduced controller will take up its role as a Hot-Standby controller because
an Active Controller already exists.
•
Similarly, removing a powered-on WLC causes both WLCs to reload. Power down the controller
that needs to be removed before disconnecting the Stack Cables to avoid this.
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Configuring EtherChannels (LAG)
•
Upload the certificate specifically on both NGWC and then pair them up. Certificates will not be
synced to the standby WLC.
Configuring EtherChannels (LAG)
The LAG, or an EtherChannel, bundles all the existing ports in both the standby and active units into a
single logical port to provide an aggregate bandwidth of 60 Gbps. The creation of an EtherChannel
enables protection against port failures and provides port level redundancy. The EtherChannels or LAGs
created are used for link redundancy to ensure HA of Access Points. Multiple LAGs can be configured
on the CT5760 WLC.
1.
Connect two CT5760 WLCs that are in powered down state using the Stack Cable.
2.
Power up and perform a boot on both controllers simultaneously or power and boot one controller.
3.
The controllers boot up successfully and form a HA pair.
4.
Configure EtherChannel or LAG on the units.
5.
Use the show etherchannel summary command to view the status of the configured EtherChannel.
6.
On successful configuration, all the specified ports will be bundled in a single channel and listed in
the command output of show etherchannel summary.
7.
Execute the show ap uptime command to verify the connected Access Points.
Link Aggregation Control Protocol (LACP) can be configured by using the lacp port-priority number
command.
Sample output of show etherchannel summary when LACP is configured is shown:
5760# show etherchannel summary
Flags: D - down P - bundled in port-channel
I - stand-alone s - suspended
H - Hot-standby (LACP only)
R - Layer3 S - Layer2
U - in use f - failed to allocate aggregator
M - not in use, minimum links not met
u - unsuitable for bundling
w - waiting to be aggregated
d - default port
Number of channel-groups in use: 1
Number of aggregators: 1
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Provisioning CT5760 for HA (Optional)
Provisioning CT5760 for HA (Optional)
The offline configuration feature can be used to provision (to supply a configuration to) a new CT5760
WLC before it is paired with the Active Controller. You can configure the stack member number, the
switch type, and the interfaces associated with a WLC that is not currently part of the HA redundant pair.
The configuration that is created on the active WLC is called the provisioned configuration. The WLC
that is paired with the active controller and that receives this configuration is called the provisioned
switch.
The provisioned configuration is manually created through the switch stack-member-number
provision type global configuration command. The stack-member-number and type on the provisioned
CT5760 must match the stack member number and type that was created for the new controller before it
is paired with the active controller.
When you configure the interfaces associated with a provisioned CT5760 WLC, the active controller
accepts the configuration and the information appears in the running configuration. However, because
the second controller is not active, any configuration on the interface is not operational and the interface
associated with the provisioned unit does not appear in the display of the specific feature. For example,
VLAN configuration information associated with a provisioned WLC does not appear in the show vlan
user EXEC command output. The provisioned configuration is retained in the running configuration
whether or not the provisioned WLC is part of the HA pair. You can save the provisioned configuration
to the startup configuration file by entering the copy running-config startup-config privileged
EXEC command.
The show running-config command output shows the interfaces associated with the provisioned WLC.
5760(config)# switch 2 provision air-ct5760-6
5760(config)# end
\\Where 2 = switch number of new CT5760, air-ct5760-6 = SKU of CT5760
5760# show running-config | include switch 2
!
interface GigabitEthernet2/0/1
!
interface GigabitEthernet2/0/2
!
interface GigabitEthernet2/0/3
<output truncated>
State Transition for AP SSO
Figure 10
Active WLC in Simplex Mode
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State Transition for AP SSO
Figure 11
Standby Insertion for HA Pairing
Figure 12
HA Sync in Progress
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State Transition for AP SSO
Figure 13
Terminal State for SSO
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Verifying HA AP SSO
Figure 14
CT5760 WLCs in Duplex SSO Mode
Verifying HA AP SSO
Verifying Redundancy States (CLI)
An Access Point Stateful Switch Over (AP SSO) implies that all the Access Point sessions are switched
over state-fully and Access Points continue to operate in a network with no loss of sessions, providing
improved network availability and reducing service downtime. The Active Controller in the redundant
pair is equipped to support 1000 Access Points and 12000 clients.
Once a redundancy pair is formed while in a stack, HA is enabled, which means that Access Points
continue to remain connected during an active-to-standby switchover.
The command show redundancy states displays all the redundancy states of the active and standby
controllers.
Manual Switchover Action (Manual Swact) i.e. the command redundancy force-switchover cannot be
executed on the Standby WLC and is enabled only on the Active Controller.
Figure 15
Redundancy State for Active WLC
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Verifying HA AP SSO
Figure 16
Redundancy State for Standby WLC
The command show redundancy displays the redundant system and the current processor information.
The redundant system information includes the system uptime, standby failures, switchover reason,
hardware mode, and configured and operating redundancy mode. The current processor information
displayed includes the image version, active location, software state, BOOT variable, configuration
register value, and uptime in the current state, and so on. The Peer Processor information is only
available from the Active Controller.
Figure 17
show redundancy on Active Controller
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Verifying HA AP SSO
Figure 18
show redundancy on Standby Controller
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Verifying AP SSO State Sync
Verifying AP SSO State Sync
AP CAPWAP state information is synced to the standby controller. AP uptime and association time can
be verified using the command show ap summary and show ap uptime on the Active and Standby
Controllers.
Figure 19
AP Summary and Uptime on Active WLC
Figure 20
AP Summary and Uptime on Standby WLC
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Viewing Switchover States (GUI)
Viewing Switchover States (GUI)
Navigate to Monitor > Controller > Redundancy > States on the controller Web UI. The Redundancy
States page is displayed:
Figure 21
Redundancy States Display on GUI
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Viewing Switchover History (GUI)
The description of the parameters in the output is given below:
Table 2
Redundancy States Display Parameters
Parameter
Description
My State
Shows the state of the active CPU controller
module. Values are as follows:
Peer State
•
Active
•
Standby HOT
•
Disable
Displays the state of the peer (or standby) CPU
controller module. Values are as follows:
Mode
•
Standby HOT
•
Disable
Displays the current state of the redundancy peer.
Values are as follows:
•
Simplex— Single CPU controller module.
•
Duplex— Two CPU controller modules.
Unit ID
Displays the unit ID of the CPU controller
module.
Redundancy Mode (Operational)
Displays the current operational redundancy
mode supported on the unit.
Redundancy Mode (Configured)
Displays the current configured redundancy mode
supported on the unit.
Redundancy State
Displays the current functioning redundancy state
of the unit. Values are as follows:
•
SSO
•
Not Redundant
Manual Swact
Displays whether manual switchovers have been
enabled.
Communications
Displays whether communications are up or down
between the two controllers.
Viewing Switchover History (GUI)
Navigate to Monitor > Controller > Redundancy > Switch Over History on the controller Web UI.
The Redundancy Switch Over History page is displayed:
Figure 22
Switch Over History Page
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AP SSO Failover Process
The description for the following parameters are displayed in the table below:
Table 3
Switch Over History Parameter Description
Parameter
Description
Index
Displays the index number of the redundant unit.
Previous Active
Displays the controller that was active prior to
switchover.
Current Active
Displays the controller that is currently active.
Switch Over Time
Displays the system time when the switchover
occurred.
Switch Over Reason
Displays the cause of the switchover.
AP SSO Failover Process
Port Level Redundancy
The 12 ports of CT5760 WLC can be connected to the infrastructure network either through a single
switch or through two switches. In either case, the ports of CT5760 WLC are configured into LAG
bundles. Failing of ports connected to neighbor switches does not induce a system switchover and it only
affects bandwidth when less than 6 ports are active. However, system switchover can occur due to
various reasons identified below.
System Level Redundancy
Process Failure Switchover
This type of switch over occurs when any of the key processes running on the Active unit fails or crashes.
Examples of this are HA Manager, WCM, Stack Manager, FED, FFM, and so on. Upon such a failure,
the Active unit reloads and the hot Standby takes over and becomes the new Active unit. When the failed
system boots up, it will transition to Hot-Standby state. If the Standby unit is not yet in Hot Standby
State, both units are reloaded and there will be no AP SSO. A process failure on the standby (hot or not)
will cause it to reload.
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AP SSO Failover Process
Power-fail Switchover
This switchover from the Active to Standby unit is caused due to power failure of the current Active unit.
The current Standby unit becomes the new Active unit and when the failed system boots up, it will
transition to Hot-Standby state.
Manual Switchover
The HA feature is enabled by default when CT5760 WLCs are connected using the stack cable and the
Cisco StackWise-480 technology is enabled. You cannot disable it; however, you can initiate a manual
graceful switchover using the command line interface. This is a user initiated forced switchover between
the Active and Standby unit. The current Standby unit becomes the new Active unit and when the failed
system boots up, it will transition to Hot-Standby state. To perform a manual switchover, execute the
redundancy force-switchover command. This command initiates a graceful switchover from the
active to the standby controller. The active controller reloads and the standby takes over as the New
Active controller.
Figure 23
Manual Switchover Command
The table below gives an estimate of the time metrics involved in the failover process:
Table 4
APSSO Failover Time Metrics
Metrics
Time
Failure Detection
In the order of 50 ms.
Reconciliation Time (Standby becoming Active)
In the order of 1020 ms.
*First Client rejoin time
Dot1x client: 64s; open client: 16s.
*All clients (12K) rejoin time
Dot1x: 228s; open clients: 153s.
*with 12K clients prior to switchover
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AP SSO Failover Process
After a Switchover
On successful switchover of the standby CT5760 WLC as active, all access points connected to the
previously active WLC must remain connected to the new Active controller.
Clients must be de-authenticated upon a switchover. This can be verified by executing the commands:
•
show ap uptime:
Verifies that the uptime of the access point after the switchover is not reset.
•
show wireless client summary:
Displays the clients connected to the new Active controller.
Upgrading an HA Pair
Prior to IOS XE Release 3.3, AP SSO was not supported on CT5760 WLCs. Upgrade individual
controllers to image version 3.3 before pairing them for HA using the guidelines explained in the Best
Practices for HA Pairing Process section.
Upgrade of an HA Pair to image versions after IOS XE Release 3.3 can be achieved by following the
steps listed below:
1.
Copy image to flash: for Active CT5760 WLC.
2.
Make sure the BOOT variable is set to reflect installed mode boot
boot system switch all flash:packages.conf
3.
Run the software install file flash:<image.bin> command pointing to the new image on the
flash to upgrade the HA Pair without having to upgrade controllers individually.
•
The Auto-Upgrade feature is not supported in this release.
•
Pairing of CT5760 WLCs running different software versions is not supported.
•
Recommendation is to upgrade both Active and Standby controllers simultaneously as explained
above.
AP SSO Hybrid Deployment with N+1 HA Topology
Figure 24
AP SSO Hybrid Deployment with N+1 Topology
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Licensing for HA with CT5760
WLAN-Controller-1
Standby
CAPWAP
CAPWAP
CAPWAP
NOC or Data Center
WLAN-Controller
WLAN-Controller-1
Primary
Aps Configured with:
Primary: WLAN-Controller-1
Secondary: WLAN-Controller
CAPWAP
CAPWAP
CAPWAP
Aps Configured with:
Primary: WLAN-Controller-2
Secondary: WLAN-Controller
WLAN-Controller-2
CAPWAP
CAPWAP
Aps Configured with:
Primary: WLAN-Controller-n
Secondary: WLAN-Controller
WLAN-Controller-n
352083
CAPWAP
A hybrid topology of AP SSO redundant pair and N+1 primary, secondary and tertiary model is
supported as shown above. The secondary controller at the DR site can be a CT5760 or a CUWN
controller running New Mobility. Access points failing back from converged access CT5760 WLC to
CUWN controllers will re-download the code before joining the CUWN WLC.
Licensing for HA with CT5760
In a HA redundant pair, the AP count is combined from license counts on both controllers. The Active
controller will display all AP licenses broken down per controller. The total number of APs that can be
supported by the CT5760 WLC HA pair is 1000.
When CT5760 WLCs are paired together to form a HA pair, the cumulative AP count may exceed 1000.
However, the WCM module on the controller does the gate keeping of not allowing more than 1000 APs
on the redundant HA pair. A warning message on the console indicates to the user that the cumulative
AP count has exceeded the maximum AP count of 1000.
In the remove case, the in-use AP count may exceed available AP count licenses on the active controller.
If the total number of APs connected exceeds the available AP count in the HA pair, syslog and warning
messages are displayed that those APs would be disconnected on AP or Stack reboot. The above can
happen if a deleted controller takes away the AP count with it or by configuration, where the customer
reduces number of adder licenses. In general, when a controller is removed from the HA pair, it takes
the previously installed AP count with it. However, the active controller will continue to support the AP
count of that lost controller in order not to interrupt the service, but upon either a controller or an AP
reboot, some APs will not be able to join back and the APs that can join the controller will fall back to
the AP count available on the active controller, i.e., the AP count licenses originally on that controller.
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AP SSO and 5760 HA-SKU
AP SSO and 5760 HA-SKU
•
The 5760 HA-SKU provides support for up to 1000 APs when Active controller Fails over to
HA-SKU unit.
•
The following notification is generated on the HA-SKU controller when a Standby non HA-SKU is
lost:
“The current stack does not support the applied AP License Count. Reconnect a Catalyst 5760 SKU
running valid AP License Count within 90 days.”
•
Two 5760 HA-SKU units cannot be connected to be paired in an SSO pair.
•
Licenses cannot be added to a 5760 HA-SKU unit.
•
The 5760 HA-SKU has a PID AIR-CT5760-HA-K9 to indicate that it is a HA-SKU unit.
•
A non HA-SKU 5760 controller cannot be converted to a HA-SKU by configuration.
The following table shows the examples of pairing controllers and their effects on the licenses for the
APs.
Table 5
Examples of Controller Pairing and Licenses
Controllers
Pairing Effect and AP Licenses
AIR-CT5760-HA-K9 SKU with
Both the units are active and the standby
controller has the HA SKU. Pairing is not
allowed. There are no licenses for an AP.
Standby: AIR-CT5760-HA-K9 SKU
AIR-CT5760-<apcount>-K9 SKU with
Standby: AIR-CT5760-HA-K9
AIR-CT5760-HA-K9 SKU with
Standby: AIR-CT5760-<apcount>-K9
AIR-CT5760-<apcount>-K9 SKU with
Standby: AIR-CT5760-<apcount>-K9
AIR-CT5760-<apcount>-K9 SKU with
AIR-CT5760-<apcount>-K9
The licenses for an AP are limited as per the AP
count on the active controller.
On AIR-CT5760-500-K9, there are 1000 APs
with a Syslog warning–AP License usage
exceeded by 500. The additional APs would
disconnect after stack reboot or AP reboot.
Active controller has licenses for 500 APs. The
standby controller has licenses for 250 APs. In
total there are licenses for 750 APs. The total AP
count is limited to 1000.
The first controller with Release 3.3 build and
second controller with EX1/CCO. Both
controllers need to have the same version of code
on them for pairing. If not, there is a mismatch.
AIR-CT5760-<apcount>-K9 SKU [DTLS image] There are two possibilities–In case of LDPE with
with AIR-CT5760-<apcount>-K9
LDPE, pairing is done. For LDPE with
non-LDPE, there is a mismatch.
Feature Intersection with AP SSO
•
Switchover during AP Pre-Image download causes the APs to start image download all over again
from the new Active controller.
•
Rogue APs and clients are not synced to Standby and are re-learnt upon switchover.
CT5760 High Availability AP SSO Deployment Guide, Cisco IOS XE Release 3.3
24
Feature Intersection with AP SSO
•
Infrastructure MFP key is not synced to the Standby controller and is re-learnt upon switchover.
•
New Active controller re-learns the shun list from IPS and other MCs, and redistributes it to the
MAs.
•
wIPS information is not synced to the Standby unit and is re-learnt upon switchover.
•
Clean Air detected Interferer devices are re-learnt after switchover.
•
Net Flow records are cleared upon switchover and collection starts fresh on the new Active
controller.
•
Mobility paths and tunnels to the MO and other peer MCs are not disrupted upon switchover.
However the Client state is cleaned up on the MO under which the HA pair exists and is re-learnt
from the new Active controller when the client re-associates.
•
Roamed clients that have their data path going through the Mobility Tunnel Endpoint (MTE)
“become Local” in case of L2 with Sticky Anchoring and L3 Roam. L2 Roamed Clients are not
affected except when roaming occurs between CUWN and CA controllers.
•
RRM related configurations and the AP neighbor list in the Leader HA pair is synced to the Standby
controller.
•
Upon Guest Anchor controller switchover, mobility tunnels stay active, APs remain connected,
clients rejoin at MA or MC, and are anchored on the new Active controller.
CT5760 High Availability AP SSO Deployment Guide, Cisco IOS XE Release 3.3
25
Feature Intersection with AP SSO
CT5760 High Availability AP SSO Deployment Guide, Cisco IOS XE Release 3.3
26
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