arp replies from two adapters of same type in a machine

Adhiraj <adhiraj@xxxxxxxxxxxxxx> · Wed, 22 Feb 2006 21:15:58 +0530

Hi all,

I have two RTL-8139 network adapters in a machine, they have these IP
addresses:
eth1: 192.168.20.1
eth2: 192.168.21.1

When I take tcpdump on these interfaces and ping to 192.168.21.1 from
192.168.21.50, I see that both the adapters reply to ARP requst sent by
192.168.21.50 machine:

/usr/sbin/tcpdump -i eth1 -vv
.
.
arp reply 192.168.21.1 is-at <MAC add of eth1>

/usr/sbin/tcpdump -i eth2 -vv
.
.
arp reply 192.168.21.1 is-at <MAC add of eth2>

Ideally eth1 should not reply to the ARP request.

Any idea why this happens?

Regards,
Adhiraj.