Cisco FEX B22 and Windows Server config

[RPMCanes]

Hello all, the user guide says to team the two adapters on the OS side, but will that generate a new MAC address for the team that needs to be accounted for on the Nexus side?

[Ian Vaughan]

Howdy,

I was going to confidently tell you about LACP having the different underlying MAC addresses on the ports and then cleverly abstracting them on the lagg / port-channel interface to make it look like one MAC. Yet again Microsoft behaviour seems a bit different to your standard network vendor as MS have chosen to present the same MAC down each link which can confuse the switch at the other end.

Bit of background reading - people have similar issues:

https://supportforums.cisco.com/discussion/11840211/nexus-2k-hp-server-lacp-issue

https://forums.juniper.net/t5/Ethernet-Switching/windows2012r2-LACP-two-nics-present-same-MAC/td-p/215073

So, in short - all things running dynamic link aggregation (LACP - sometimes called switch assisted or switch dependant) "should just work", however back in the real world you might need to create a lab environment and do a bit of old fashioned trial and error to make sure that all of the speeds feeds and timers match up and allow the auto-magic to happen.

Hope that helps (feel free to give Kudos if it does).

Thanks

Ian