Marty, And I forgot to ask below, any thoughts as to whether or not the echo *replies* are somehow bounced off of the distant-end router too? That is what I found the most difficult to accept and was stretching for a theory that might possibly explain it.
Thanks again, Scott s vermill wrote: > > Marty Adkins wrote: > > > > > I'm not totally sure what you mean by "from a local ethernet > > interface". > > If you mean that the router forwarded a packet that arrived on > > its > > Ethernet interface, and the destination was its serial IP, > then > > the > > packet will definitely *not* leave the router. > > As you surmised, this was sourced from the ethernet interface > using an extended ping - it did not arrive there from somewhere > else. > > > > > OTOH, if the router itself is the source of the packet, and it > > pings > > its own serial IP, and the outbound interface and layer 2 > encap > > are > > resolved and unambiguous, then the router will launch the > packet > > out that p2p interface or PVC. I have done exactly what > > Priscilla > > describes, and not only seen the output from "debug ip icmp" > on > > the > > neighbor router, but also observed it generating ICMP > > redirects, since > > the packet was forwarded out the interface it arrived on! > > I too have done what Priscilla tried and did not see the debug > output. > > > > > This Cisco aberation is extremely useful for troubleshooting > > p2p WAN > > links. When the path has been looped (line protocol up > > (looped)), the > > only IP that is pingable is the directly connected one. That > > the router > > actually sends the packet makes it possible to test the link > > with ping. > > That, sir, is an excellent thing to remember. I never thought > about it, but it sure is useful. Many thanks. > > > > > Now I wasn't performing an extended ping and sourcing the ping > > from a > > different interface. Maybe that's the difference? I last did > > this > > with IOS 12.0(7)T. > > > > Priscilla, I'm not saying what you observed is wrong! I don't > > have > > access at the moment to replicate it, but I'm positive of what > > I saw -- > > I had my students do it in class numerous times. > > > > - Marty > > > > > > Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=53163&t=53148 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
