gratiutous ARP with arping
From thelinuxwiki
to manually send a gratuitous ARP to the broadcast address, run...
# arping -U 192.168.100.50 -I eth1 -c 1
if you receive an error...
bind: Cannot assign requested address
then you need to enable non local ip binding
# echo 1 > /proc/sys/net/ipv4/ip_nonlocal_bind
to make the setting permanent,
# echo "net.ipv4.ip_nonlocal_bind = 1" >> /etc/sysctl.conf
