UCS FI traffic flow

[nflnetwork]

Hello,

where in UCS manager do i verify that all traffic is "flowing' thru both fabric's ?

we are migrating a pair of 6200 Fi's and before we disable one side of the fabric i wanted a to perform a quick sanity check that exiting traffic  is actually flowing across both fabric simultaneously. (<< this is how it's designed to work correct and not just one at a time???) 

[Steven Tardy]

That really depends on the configuration.

• Are your vNICs configured for UCS Fabric Failover (then that vNIC will only use one FI at a time)?
• Are you vNICs configured one for each Fabric Interconnect and teaming/bonding/etc at the OS layer? (Need to make sure the proper teaming options are used.)

Both Fabric Interconnects can be used simultaneously for multiple endpoints (MAC Addresses) but NOT by the same endpoint (MAC Address).

I would check the MAC tables on each Fabric Interconnect by following something like "Tracing the Path in UCS" (starting on page 37):

• https://www.ciscolive.com/c/dam/r/ciscolive/us/docs/2017/pdf/BRKINI-2011.pdf

[nflnetwork]

@Steven Tardy 

I would say that vNICS are configured one for each Fabric Interconnect and teaming is done at the OS layer. 

Also the link you posted does not work .

[Steven Tardy]

Odd the link is now broken. Can google the filename to get versions of that file from newer Cisco Live events (the page number is different):

• https://www.ciscolive.com/c/dam/r/ciscolive/emea/docs/2018/pdf/BRKINI-2011.pdf

If active/backup load balancing is used it is hard to 100% know/test without potential disruption.

For active/active (MAC address pinning, the ESXi default) for VM network vNICs, make sure both FIs see some of the VM MAC addresses.

Things I would check before doing anything:

• Do MAC addresses match between UCSM vNIC and OS NIC? Often ESXi will "shuffle" NICs so one assumes UCSM vNIC4 = OS NIC4 which can be an incorrect assumption.
• Are VLANs allowed on one vNIC pair allowed on the other vNIC?
• Is the proper OS NIC teaming used? (UCSM does NOT allow some active/active teaming, LACP).
• Are MACs seen on the FI in VLANs as expected?

Beyond that it would be a test to verify.

[emaben]

Here's the Cisco live link: 

https://www.ciscolive.com/c/dam/r/ciscolive/emea/docs/2019/pdf/BRKINI-2011.pdf