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RHEL6 FCOE / nc553m / FEX questions.

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RHEL6 FCOE / nc553m / FEX questions.

Jason is looking to help a customer with FCoE (Fibre Channel over Ethernet) issues:




I have a customer who is having problem getting FCOE configured with FEX (connected to Nexus 5k) and nc553m’s.


According to the RHEL FCOE config gude:



Do not run software-based DCB or LLDP on CNAs that implement DCB.

Some Combined Network Adapters (CNAs) implement the Data Center Bridging (DCB) protocol in firmware. The DCB protocol assumes that there is just one originator of DCB on a particular network link. This means that any higher-level software implementation of DCB, or Link Layer Discovery Protocol (LLDP), must be disabled on CNAs that implement DCB.


Which leads me to the question on the nc553m.


Does the nc553m implement DCB in FW?


The reason I ask, is that if we configure OS DCB and llpdap then the CNA does not even FLOGI to the fabric.


If we disable DCB and llpdap, the CNA does the auto Vlan discovery, the FLOGI but then goes “offline” and cannot see zoned targets.  Which is the second problem.


If anyone has some good docs on how to get this to work, or has experience in RHEL FCOE configs please let me know ASAP.




Input from Chris:




Yes, the NC553m is a DCB compliant adapter.  You would not use software-based FCoE or LLDPX on the host for FCoE storage.  When the FCoE partition of the adapter is enabled, it will appear in the host OS as an FC adapter.  The lpfc820 device module would be required for operation, which is included in RHEL 5.7 and newer.


Did they go into the NC553 boot BIOS and enable the CEE function (that’s what Emulex calls it in the BIOS?)




Any more comments or suggestions for Jason?