Today I found some interesting technical details during my installation of Cisco UCS for the client. FCoE architecture are slightly different when you decide to uplink the FCoE traffic end to end to the Cisco Nexus 5000 unified fabric, or you are doing the FC uplink directly from the UCS 6120 to the MDS or SAN fabric switches. I went through the documentation and my previous round of installation, we were actually configure the LAN & SAN uplink from UCS 6120 to Nexus 5k. Therefore, in our configuration, we required to have specified FCoE VLAN which carry the FCoE traffic to reach the storage through Nexus 5000. Today, I implemented the similar configuration, but the different was the uplink configuration.

This new setup are included with 10 G Ethernet uplink from UCS 6120 to Catalyst 6509 through Fiber, and utilizing FC Uplinks from UCS 6120 to MDS 9124. In my test, I removed the VLAN that I created purposely for FCoE, and found that there are no impact to the configuration.  I had confirmed with the support guys that if you are doing an uplink with FC from UCS 6100 to MDS, you will not require to tag the specified VLAN that created for the VSAN in the configuration.