Cisco 9800 WLC High Availability Configuration

The redundancy explained in this article is 1:1, which means that one of the units operates in Active state while the other operates in Hot Standby state.

If the active box is detected as unreachable, the Hot Standby unit becomes active and all APs and clients maintain their service through the new active unit.

Once both units are synchronized, the standby 9800 WLC mimics its configuration with the primary unit.

Any configuration change performed on the active unit is replicated on the standby unit via the Redundancy Port (RP).

Configuration changes are no longer allowed to be performed on the standby 9800 WLC.

Besides the synchronization of the configuration between boxes, they also synchronize:

Restrictions

Before you enable HA between two 9800 WLCs, perform these validations:

Prerequisites

Requirements

Cisco recommends knowledge of 9800 WLC basic operation.

Components Used

The information in this document is based on these software and hardware versions:

The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, ensure that you understand the potential impact of any command.

Configure HA on 9800 WLC Hardware Based

Configure HA on virtual 9800 WLCs

Connect 9800 WLCs to the network and ensure they are reachable by each other.

Connect RP as shown in the network topology. There are two options to connect 9800 WLCs RP:

Save configurations on both 9800 WLCs

Restaart both unit at the same time

Verify the current configuration with this command:

Step 4. Save configurations on both 9800 WLCs

Step 5. Restaart both unit at the same time

To enable HA, link both virtual 9800 WLCs to the same redundancy network.

To verify that both boxes run the same version, assign the redundancy IP address to both 9800 WLCs.

To manually specify which box must be the active 9800 WLC, set the Active Chassis Priorityeither by GUI or CLI.

To save configurations on both 9800 WLCs, reload them.

In order to break HA on both boxes, clear the redundancy configuration of the current active 9800 WLC and force a redundancy switchover.

After that, the second box restarts and comes back with new IP address configuration (to avoid IP address duplication with the former HA 9800 WLC) and with HA configuration cleared. The original active 9800 WLC keepts its original IP address.

To synchronize the state of two hardware 9800 WLCs in an HA pair, you can use the web UI or the CLI.

The web UI takes care of software distribution to both controllers in the pair and installs and reboots both units at the same time.

This causes identical downtimes on both units.

After both 9800 WLC units have rebooted and are synced to each other, you can access them via console and verity their current state.

The '*' points the chassis from which you run the command.

You can verify the current data from both active and standby 9800 WLC, to ensure it is the same on both.

The key facts from the text above in 10 sentences: