Disabling the Fabric WWN Verification Check

When a QFX Series NP_Port sends a fabric login (FLOGI) request to a Fibre Channel (FC) switch, the FLOGI accept (FLOGI-ACC) reply from the FC switch contains the SAN fabric worldwide name (WWN). The QFX Series uses the SAN fabric WWN in the multicast discovery advertisement (MDA) that the QFX Series sends to the ENodes in the FCoE network.

However, some FC switches substitute their own WWN (often the FC switch’s virtual WWN) for the SAN fabric WWN in the FLOGI-ACC message. In this case, different NP_Ports that log in to the same FC fabric might receive different fabric WWNs in the FLOGI-ACC messages if the NP_Ports are connected to different FC switches in the SAN fabric.

If the QFX Series receives different fabric WWNs on NP_Ports that are connected to the same SAN fabric, the QFX Series uses the first fabric WWN it receives in the MDA it sends to the ENodes. The QFX Series isolates the NP_Ports that receive a different fabric WWN from other FC switches in that SAN fabric. No ENode sessions are assigned to the isolated NP_Ports. FC traffic is assigned only to NP_Ports that receive a fabric WWN in the FLOGI-ACC message that matches the fabric WWN received by the first NP_Port to log in to the FC fabric. (If an NP_Port receives a fabric WWN that does not match the fabric WWN received by the first NP_Port to log in to the FC fabric, it does not carry traffic to the SAN fabric.)

To prevent ENodes from being isolated due to a mismatched fabric WWN, you can disable the gateway fabric WWN verification check. Disabling the fabric WWN verification check enables all NP_Ports connected to a SAN fabric are used to carry traffic between the gateway and the FC switch, regardless of the fabric WWN the NP_Port receives in the FLOGI-ACC message.