Are ARP queries like “Who is 10.2.2.2, tell 11.1.1.1” valid?

[ananda123]

Are ARP queries like “Who is 10.2.2.2, tell 11.1.1.1” valid?

RFC itself doesn’t tell that a arp query cannot be done for IP addresses outside of a hosts subnet.

Please correct me if I am wrong with the above assumption.

I have seen some routing devices, which responds with its own MAC address when it gets a ARP query from a host connected to its interface,

for an IP outside of the subnet.

Linux versions FC8, doesn’t care or validate which source IP it uses to do a ARP query if there are multiple IPs in different subnet in that Linux host. In such a case getting a reply is unpredictable.

Please share your views on this and prior experience if you have seen the behavior in other devices.

[cadet alain]

Hi,

Are ARP queries like “Who is 10.2.2.2, tell 11.1.1.1” valid?

I have seen some routing devices, which responds with its own MAC address when it gets a ARP query from a host connected to its interface,
for an IP outside of the subnet.

If you put a static route on a multipoint interface pointing to interface( not to next-hop) then you will observe such arp queries and if you get a

response from the router this is because it has proxy-arp enabled on it's interface.

Regards.

Alain.