[ubuntu] IP aliasing problem on multihomed system

Hi,

I have a multihomed server (Box1) ruing Ubuntu 12.04 with two etheet ports (eth2 and eth3) coected to the same subnet. I create an IP alias using

ip addr add AA.BB.CC.DD /28 dev eth2:0

on interface eth2. The IP address AA.BB.CC.DD is also on the same subnet. Ruing 'ip addr' displays AA.BB.CC.D as an additional IP along with the original IP address on eth2. Next, I sendgratuitous arp to publicise the new IP address using

arping -bA -c 1 -I eth2 AA.BB.CC.DD

On a different box (Box2) ruing Ubuntu 12.04 and on the same subnet, "arp -n" shows the correct association between IP address AA.BB.CC.DD and MAC address of eth2. But from this box I can't ping AA.BB.CC.DD. So, I run

arp -d AA.BB.CC.DD

which removes the arp entry from the cache on Box2 and ping again. The pings then succeed and get a response. But looking at the arp cache now on Box2, using "arp -n", I see the MAC address of eth3 (vs eth2) of Box1 associated with AA.BB.CC.DD. If I again send a gratuitous arp with eth2 from Box1, which restores MAC address of eth2 in the arp cache of Box2, the pings stop working again. It seems the IP alias is getting done on eth3 rather than on eth2 on Box1, even though "ip addr" shows it being assigned to the correct interface eth2.

I'll appreciate if someone can explain what is happening here and how to correct this problem.

Thanks.