Your mileage with this problem will vary depending on your network topology.  If your connecting an ESX Server to Nexus on a single portchannel you probably won't ever see a probelm even with Beacon Probes enabled.  If you have dual portchannels like...

ESX VLAN Beacon Probing can cause up-port flooding behavior if the vSwitch looses beacons.  This is called 'shotgunning' in VMware's terminology.When we hooked up our HP blade centers to Nexus, we had occassional events when DRS would vMotion a VM an...