Use the Cluster Detail Edit to change the name of the cluster and assign a different server to be the primary cluster member.
Click Devices > Access Gateways > [Cluster Name] > Edit.
Modify the following fields:
Name: Specify a name for the cluster.
Description: Specify the purpose of the cluster. This is optional, but useful if your network has multiple Access Gateway clusters.
Primary Server: Indicates which server in the cluster has been assigned to be the primary server. To change this assignment, select the server from the drop-down list. For more information about this process, see Changing the Primary Cluster Server.
Click OK.