This typically happens when a VLAN or VLANs is not properly defined on the controller(s) or the VLAN is not properly defined on the uplink switch
All cluster members will probe each VLAN for connectivity. If they do not see each other on every VLAN, except those configured here, they will only form a L3 cluster
You can run the “ show lc-cluster vlan-probe status”
Thank you
Victor Fabian
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