Let me see if I got this. Route A: unknown networks behind it uses 10.10.10.2 as a neighbor to router B Router B: has a network 172.16.16/24 uses 10.10.10.1 as a neighbor to router A. Router A's table shows 172.16.16/24 -> 10.10.10.2 You want Router A to ARP and pretend its on the local broadcast domain for the 172.16.16/24 prefix. But that prefix is NOT local to router A, thus it must ROUTE and thus uses the NexHop in its table. It seems you description is wrong.... But I don't know.. Please clarify On Sun, Oct 06, 2002 at 12:44:07PM -0400, Ralph Doncaster wrote:
Background: Router A and B are connected via a common ethernet segment 1. Router A uses 10.10.10.1/30, and Router B uses 10.10.10.2/30. Router B also has another subnet configured for ethernet segment 1; 172.16.16.0/24.
When I setup a situation like the above, with Router B advertising the 172.16.16.0/24 to router A, router A sees a next hop of 10.10.10.2. This is not good since packets from A going to the 172.16.16 subnet get sent to Router B, which then ARPs the desitnation, instead of just being ARPed by router A.
I don't want to turn on ICMP redirects on B since they're insecure and ugly. I've also made sure I'm not using next-hop self. Is there a way to make this work?
Ralph Doncaster principal, IStop.com