Node A is a member of SAN Zone 1 and SAN Zone 2. Node B is a member of SAN Zone 2. Node B has just been replaced and the storage administrator is troubleshooting connectivity issues between Node A and

Nodes can indeed be members of multiple SAN zones, which is a common and flexible configuration in Fibre Channel environments.

While possible, a physical misconnection or unauthorized host is less likely to be the primary cause of connectivity issues immediately after a hardware replacement than an outdated zone configuration referencing the old hardware's WWN.

Registered State Change Notifications (RSCNs) inform devices of changes in the fabric, but an issue with zone configuration not including a new WWN is a more direct and likely cause of initial connectivity failure than undesired RSCN events themselves.

Fibre Channel zones are typically configured using the unique World Wide Names (WWNs) of the Host Bus Adapter (HBA) ports. When Node B is replaced, its new HBA will have a different WWN than the old one. The existing SAN zone configuration, which still references the old WWN, will therefore not include the new Node B, preventing it from communicating with Node A.