I am also a bit leery of setting it much lower than the defaults due to the possibility of filtering something my customers will care about... I am not sure what the best strategy is but what really bit a couple of our customers was their old IOSes that tore the sessions down. I note that most of our customers speaking BGP had no issue just three out of about 25.
What do people think is a reasonable maximum as-path length to enforce at ones edge? John van Oppen Spectrum Networks LLC Direct: 206.973.8302 Main: 206.973.8300 Website: http://spectrumnetworks.us -----Original Message----- From: Leland E. Vandervort [mailto:lel...@taranta.discpro.org] Sent: Monday, February 16, 2009 9:53 AM To: Jon Lewis Cc: John van Oppen; nanog@nanog.org Subject: RE: anyone else seeing very long AS paths? bgp maxas-limit has a default value of 75 if you don't include it explicitly in the config so in this case it wouldn't have made much of a difference. L. On Mon, 16 Feb 2009, Jon Lewis wrote: > On Mon, 16 Feb 2009, John van Oppen wrote: > > > Yep we saw the same, every customer with old IOS had their sessions die > > to us at the same time... That always makes for an interesting time > > when watching the NMS system... > > Is there a reason you don't use something like "bgp maxas-limit NN" on > your transit sessions? > > We saw this too, but it stopped at our transit routers. There was > actually another a few days ago. > > Feb 13 18:46:07: %BGP-6-ASPATH: Long AS path 4323 1299 12887 12741 39412 > 39625 39625 39625 39625 39625 39625 39625 39625 39625 39625 39625 39625 > 39625 39625 39625 39625 39625 39625 39625 39625 39625 39625 39625 39625 > 39625 39625 39625 39625... > > Feb 16 11:24:53: %BGP-6-ASPATH: Long AS path 4323 3257 29113 47868 47868 > 47868 47868 47868 47868 47868 47868 47868 47868 47868 47868 47868 47868 > 47868 47868 47868 47868 47868 47868 47868 47868 47868 47868 47868 47868 > 47868 47868 47868 47868... > > > ---------------------------------------------------------------------- > Jon Lewis | I route > Senior Network Engineer | therefore you are > Atlantic Net | > _________ http://www.lewis.org/~jlewis/pgp for PGP public key_________ >
