Dell W-7010 AOS 6.4.x User Guide - Page 140

Replacing a Redundant Master Controller The control plane security feature requires you to synchronize databases from the primary master controller to the backup master controller at least once after the network is up and running. This ensures that all certificates, keys, and whitelist entries are synchronized to the backup controller. Because the AP whitelist may change periodically, you should regularly synchronize these settings to the backup controller. For details, see Configuring Networks with a Backup Master Controller on page 135. When you install a new backup master controller, you must add it as a lower priority controller than the existing primary controller. After you install the backup controller on the network, synchronize the database from the existing primary controller to the new backup controller to ensure that all certificates, keys, and whitelist entries required for control plane security are added to the new backup controller configuration. If you want the new controller to act as the primary controller, you can increase that controller's priority after the settings have been synchronized. Replacing Controllers in a Multi-Master Network Use the following procedures to replace a master or local controller in a network environment with a multiple master controllers. Replacing a Local Controller in a Multi-Master Network The procedure to replace a local controller in a network with multiple master controllers is the same as the procedure to replace a local controller in a single-master network. To replace a local controller in a multi-master network, follow the procedure described in Replacing a Local Controller on page 138 Replacing a Cluster Member Controller with no Backup The control plane security feature allows APs to fail over from one controller to another within a cluster. Therefore, cluster members or their local controllers may have associated APs that were first certified under some other cluster member (or the cluster root). If you permanently remove a cluster member whose APs were all originally certified under the cluster member being removed, its associated APs do not need to reboot in order to connect to a different controller. If, however, you remove a cluster member whose associated APs were originally certified under a different cluster member, those APs need to reboot and be re-certified before they can connect to a different controller. If the cluster member you are removing has local controllers, the local controllers also reboot so they can be updated with new certificates, then pass the trust update to their terminating APs. To replace a cluster member that does not have a backup controller: 1. On the cluster master to be removed, clear the cluster root IP address by accessing the command-line interface and issuing the no cluster-root-ip ipsec command. 2. Remove the cluster member from the network. 3. If the cluster master you removed has any associated APs, you must reboot those APs so they receive an updated certificate. 4. If the cluster member you removed has any associated local controllers, reboot those local controllers so they receive a new certificate and then pass that trust update to their APs. 5. Remove the cluster master from the cluster root's master controller list by accessing the command-line interface on the cluster root and issuing the whitelist-db cpsec-master-switch-list del mac-address command. This step is very important. Unused local controller entries in the local controller whitelist can significantly increase network traffic and reduce controller memory resources. Dell Networking W-Series ArubaOS 6.4.x | User Guide Control Plane Security | 140