Refreshing ARP table entries

Taking an IP address down on one host:

/sbin/ifconfig eth0:1 down

Taking the IP address up on another host:

/sbin/ifconfig eth0:1 netmask up

Use arping to update the ARP tables:

/sbin/arping -S -B

So the switch should cache the new arp entry invalidating the existing one.
The arping utility appears to be part of the iputils package which should already be installed but if not:

yum install iputils