Gluster - State: Peer in Cluster (Disconnected)

Issue

Gluster peer status returns one or more nodes as:

State: Peer in Cluster (Disconnected)

Re-Probing may show:

[root@localhost ~]# gluster peer probe n.n.n.n
peer probe: success. Host n.n.n.n port 24007 already in peer list

While attempting to detach the peer may show:

[root@localhost ~]# gluster peer detach n.n.n.n
peer detach: failed: One of the peers is probably down. Check with 'peer status'