I just can't seem to let go of things. I got the same pod, 109, this evening and retried the scenario, and sure enough it didn't work. All I can say is that the version on R1 of the pod is an earlier 12.4(3a) release.
Ok, I'm dropping it for real now... On Fri, Jul 10, 2009 at 12:23 PM, jmangawang<[email protected]> wrote: > Aargh! Ok, so I just set this up on Dynagen, using two 2691s running > 12.4(23) and, of course, it works. Then I copy/pasted the configs for > R1 and BB1 from the actual lab (with modifications for the > interfaces), and it worked, too. > > I also learned something about how ebgp-multihop and ttl-security > work, and they are inversely related to each other. ebgp-multihop > sets outgoing packet's TTL to the value specified, ie. ebgp-multihop > 2, sets the TTL to 2. On the flip side, ttl-security receives packets > whose TTL is 255 minus the set value, ie. ttl-security hops 2 expects > the TTL on the incoming packet to be 253 (255 - 2). So, if you have > eBGP configured and you initially started out both sides with > ebgp-multihop 2, then later changed one of them to TTL-security, your > BGP session would never come up. The solution would be to set > ebgp-mulithop to 255, or just use ttl-security on both sides. > > I better get one of these on the real lab... :) > _______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com
