You read the C-Series Documentation front to back, double-checked your cabling from the VIC (P81E) Card to the UCS Fabric Interconnect, triple-checked your Gb connection from the C-Series management ports to the Fabric Extender, but your Rackmount UCS Servers are still not showing up in UCS Manager…What is going on?
You may be trying to connect your management (CIMC) ports, M1 and M2 to the FEX instead of the LOM ports on the Server.
It seems logical, right? The 1Gb connections to the FEX are for C-Series Management traffic. So, I should connect M1 to FEX A and M2 to FEX B? Not exactly.
Ports 1 or 2 of the LOM should be connected to the FEX connected to Fabric Interconnect A
Ports 3 or 4 of the LOM should be connected to the FEX connected to Fabric Interconnect B
By the way, the port numbering on the P81E Converged Network Adapter card may be a little confusing: The higher numbered port (Port 1) is on the left, and the lower numbered port (Port 0) is on the right.
The correct way to cable the P81E Card to the Fabric Interconnects is to attach the left port (Port 1) to Fabric Interconnect A and the right port (Port 0) to Fabric Interconnect B.
You may think that you should follow numerical order and connect Port 0 to Fabric Interconnect A and Port 1 to Fabric Interconnect B. However, that would be incorrect, and UCS Manager will warn you accordingly (“incorrect cabling” or something like that).
There is a detailed write-up of the procedure as well as some helpful graphics at Cisco.com