In reply to simon gordon.

No, the definition still stays the same. You raise an excellent point. This specific example is, in reality, a single-hop deployment as the FI is put into NPV mode and the upstream NPIV switch is the one connected via E-port to the core switch. That is, the Domain ID encompasses the FI, and there is only one ISL in this topology.

However, the option also exists to have the FI in FC-SW mode, connecting via VE_Port to the upstream switch, maintaining separate FCIDs and creating ISLs. From a configuration standpoint, it takes no more or less time to set up.