eBGP TTL matching requirement


Is there a TTL value enforcment on EBGP session establishment? For some
reason I thought that both peers have to have the SAMe value? Is that
true? For example:

default EBGP = TTL = 1 (if one end sends something other than 1 in its OPEN
message, we won't bring up the adjecancy)
multihop EBGP = TTL = 255 (by default) - likewise, if one end sends
something else, adjecancy won't come up
multihop EBGP = TTL = modified hop value - ex. 15 (both ends have to have

I understand that ttl-security and its implications.




Concur, but the original poster should also look at the GTSM, which doesn't do what he asked about but which does make use of TTL as a validation mechanism: