Adding Remarks to an Access Control List (ACL)
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Configuring Backup Cisco Wireless Network Controllers

Due to the importance of having an active controller, you should not rely on only a single controller to support your Cisco wireless network. Controllers may be distributed between a central site and regional sites and still manage all APs anywhere on the network.

Controllers at the central site and regional sites do not need to be in the same mobility group, and using the CLI on the controller you can specify a primary, secondary, and tertiary controller for your lightweight access points.

Starting with controller software release 5.0, you can configure timers for the primary and secondary controllers so that the time taken to discover a failed primary controller is reduced. If, during that timed interval, a controller has not received any data packets from the other controller, it then sends an echo request to the controller.

If there are no results from the echo, the controller considers the other controller to be failed. From the lightweight access point’s perspective, if a controller fails two consecutive discovery requests, it is considered to be failed.

In all failure cases, the secondary and then the tertiary controllers are attempted to be contacted. When the primary controller comes back on line, the access points automatically fail back over to the primary controller. To configure backup controllers, follow these steps:

  1. Configure a primary controller for a specific access point:

    config ap primary-base controller_name Cisco_AP [controller_ip_address]
  2. Configure a secondary controller for a specific access point:

    config ap secondary-base controller_name Cisco_AP [controller_ip_address]
  3. Configure a tertiary controller for a specific access point:

    config ap tertiary-base controller_name Cisco_AP [controller_ip_address]
  4. Configure a primary backup controller for a specific controller:

    config advanced backup-controller primary backup_controller_name backup_controller_ip_address
  5. Configure a secondary backup controller for a specific controller:

    config advanced backup-controller secondary backup_controller_name
  6. Configure the fast heartbeat timer for local, hybrid-REAP, or all access points:

    config advanced timers ap-fast-heartbeat {local | hreap | all} {enable | disable} interval
  7. Configure the access point primary discovery request timer:

    config advanced timers ap-primary-discovery-timeout interval
  8. Save your changes:

    save config
  9. Verify the configuration changes that you made by using these commands:

show ap config general Cisco_AP
show advanced backup-controller
show advanced timers
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