Dual-homed upstream switch & duplicate packets

[jconides]

I have a 1000v connecting to a pair of Nexus 2K that are dual-homed, as opposed to vPC. This pair is responsible for the packet and control L2 traffic. The 1000v uplink port-profile is set to 'channel-group auto mode on mac-pinning'.

The network admin told me he is concerned about the possibility of duplicate packets being sent across the 2Ks. He is planning on changing the config to a virtual port-channel in the future, but must wait for a bit.

My understanding is that mac-pinning should work in this case, according to the port profile config guide.

Thanks,

John

[lwatta · Accepted solution]

MAC Pinning is fine in this situation. The VEM module on the ESX host is smart enough to know whats going on and will prevent it from happening.

There is a great description in the following guide that explains it better than I can

http://www.cisco.com/en/US/prod/collateral/switches/ps9441/ps9902/guide_c07-556626.html

Search for "loop prevention" and read from there. Lots of good info on how we prevent loops and how you will not see duplicate packets if use MAC Pinning.

louis