[c-nsp] unusual arp behavior

[Alexey Toptygin]

<a friend recommended that I ask on this list, sorry if this is the wrong
place>

I have noticed that some (all?) cisco routers don't respond to ARP 
requests if the requestor IP address is not in the subnet of that router. 
RFC826 doesn't specify this behavior, and I haven't seen any other devices 
do this. It also breaks duplicate address detection on DHCP clients, which 
uses 0.0.0.0 as the requestor IP address.

Can anyone tell me why this behavior is present? Is there a way to turn it
off?
 			Alexey