eBGP TTL matching requirement

Vitto Capabianco donvittony at gmail.com
Tue May 11 12:55:02 CDT 2010


Folks,

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
it)


I understand that ttl-security and its implications.

Thanks,

Vitto



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