So you migrated an ip from one machine to another and in the process invalidated the arp table in the upstream switch that
you don't control
You can use arping with a broadcast on the new machine to invalidate the cache on the upstream (and other switches)
Thanks for the heads up Robert!
Some have -B for broadcast (see venerable man pages): arping -S <ip> -B actually, carp does it like this (iputils under Linux) arping -q -I eth0 -U <ip> ---- update note ---- Later versions of arping under Ubuntu have used the -S, so they are in line with the BSD version. Not sure if the package name changed, or just that utility, so be warned - and heck try either version...
If you are stuck on Windows, you could try Nmap like this:
Stolen from here http://serverfault.com/questions/69890/is-there-any-way-to-arp-ping-on-windows
nmap -PR -sP <host>