As I was studying for the Troubleshooting Cisco Data Center Unified Fabric (DCUFT) exam, I came across a couple of low level NX-OS commands that can help determine whether the Data Center Bridging eXchange (DCBX) protocol is functioning correctly. Being able to verify the operation of DCBX is important when troubleshooting FCoE, because the proper operation of the Data Center Bridging (DCB) extensions is a prerequisite for FCoE.

Unfortunately, the output of these commands is rather cryptic, because it essentially shows the content of the DCBX TLVs as raw hex dumps, rather than nicely decoding the fields in the output of the command. Because I still wanted to understand how to read the DCBX information contained in these commands, I decided to dive a bit deeper into the DCBX protocol. Continue reading →