When turning up a new port on a 2248 FEX, when the "private-vlan host association primary secondary" command is put on an interface BEFORE the server is cabled up, the interface goes into an "inactive" state and will not come up by bouncing the port. However, when the pvlan host association command is removed and re-added, the interface then comes up right away.
I haven't found any Cisco documentation describing the issue. Does anyone know if this is a bug? Has anyone else seen this issue?
I don't understand why the port must be cabled up before adding pvlan configuration.
Best Answer
Whenever you're configuring a FEX switchport, you must ensure that the configuration is consistent across both parent switches (i.e. Nexus 5K). You can do this manually or use the config-sync feature to simplify your configuration.
For instance:
HOWEVER - you must repeat this configuration on the same port on the other control plane (other Nexus parent switch) because the configurations are not sync'd automatically by default.
If the configuration for a FEX switchport doesn't match on both parent switches, it will place it into "inactive" state as you describe.