I have recently just watched an excellent Cisco Live video on UCS performance troubleshooting which demonstrated how to trace network traffic within Cisco UCS. The speaker made a comment though, in order to determine which NIF is used by a VIF when port-channels are used between the FEX and FI there are different commands to run. Need to determine the load-balancing hash result. Unfortunately he never went into what these commands were.
So when we have veths pinned to port-channels instead of HIFs and NIFs, what commands will show which path is being used?
Just care about the first part :
ucs-A(nxos)# show port-channel load-balance
Port Channel Load-Balancing Configuration:
With the command " A(nxos)# sh inter vethernet XXX " you can see the "Bound Interface" and after that you may run:
A(nxos)# show system internal fex info satport ethernet 1/1/1 <<< this will show you something like this:
FABRIC-A(nxos)# show system internal fex info satport ethernet 1/1/1
Interface-Name ifindex State Fabric-if Pri-fabric Expl-Pinned
Eth1/1/1 0x1f000000 Up Eth1/1 Eth1/4 Eth1/1
Dev: 0 Nif3 <<<< Hif7 <<<<<< (Nif:0x20000000 Hif:0x1f000000)
NIF = interface from the IOM to the FI
HIF = interface from the blade's adapter to the IOM's backplane
Let me know if you have more questions :)
you may use this commands:
B(nxos)# sh port-channel load-balance << this will tell you the load balance method used
If you are using source-dest-ip like in my case, you may use this command:
B(nxos)# sh port-channel load-balance forwarding-path interface port-channel ID vlan ID src-ip x.x.x.x dst-ip y.y.y.y and it will show you something like this:
Missing params will be substituted by 0's.
Load-balance Algorithm on switch: source-dest-ip
crc8_hash: 109 Outgoing port id: EthernetX/Y <<< this is what you are looking for now
Param(s) used to calculate load-balance:
For the blade, it depends on which the active vNIC is, for the FEX it depends on the pinning based on the blade slot the server is in. Odd servers go through odd links and even servers go through even ports.
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