At 12:01 AM 3/5/02, Hunt Lee wrote: >TCP / IP Vol1 by Jeff Doyle says if a subnet is summarized by a summary >address, the subnet's instability will no longer be advertised. But if this >is the case, then what happens if:- > >e.g. Router A advertised a summary route (advertising subnet 172.20.10.0 >/24 to Router B. Now if a host in that subnet (say 172.20.10.1 is >bouncing) - if this instability is hidden by the summary route, does it mean >that Router B wouldn't realized that 172.20.10.1 is flapping, and continues >to forward packets to it?
Sure. It happens all the time. Bouncing hosts are rarely a concern of routing protocols or of non-local routers. The final router that needs to forward to the host would ARP for it and not get an answer. That router wouldn't tell anyone else there was a problem though. Well, I take that back. It might send an ICMP Host Unreachable to the sending end host. Routers wouldn't pick up on this though. Routers care about the reachability of networks, subnets, summarized supernets. (A host-specific route is an exception.) I'm not sure if that's what you meant to ask, though. It has nothing to do with summarization. It's just normal behavior.... Priscilla >Please help... > >Best Regards, >Hunt Lee ________________________ Priscilla Oppenheimer http://www.priscilla.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=37334&t=37228 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
