North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: Strange BGP announcement.
At 07:30 AM 11/9/98 -0600, Brett Frankenberger wrote: >:: Scott Gifford writes :: >> >> > > > Bays don't crash (at least not in the general case ... for example, >> > > > mine stayed up this time and the last time this happened), but they do >> > > > send a NOTIFY and bring down the BGP session, as required by the RFC. >> > > > (I believe gated does this also.) >> >> In case any Bay Networks users didn't already know this, reasonably new >> version of the system software have a switch to turn off this behavior: >> >> 1:TN]$g wfBgpPeerEntry.41.* >> wfBgpPeerEntry.wfBgpPeerASLoopDetect.157.130.101.182.157.130.101.181 = 2 >> wfBgpPeerEntry.wfBgpPeerASLoopDetect.204.70.16.38.204.70.16.37 = 1 >> wfBgpPeerEntry.wfBgpPeerASLoopDetect.204.70.100.66.204.70.100.65 = 1 >> wfBgpPeerEntry.wfBgpPeerASLoopDetect.209.54.51.230.209.54.51.229 = 2 >> wfBgpPeerEntry.wfBgpPeerASLoopDetect.209.54.101.238.209.54.101.237 = 2 >> >> [1:TN]$set wfBgpPeerEntry.wfBgpPeerASLoopDetect.204.70.100.66.204.70.100.65 2 >> (41) (interface) >> [1:TN]$commit >> >> Set this flag to '2' for each interface to keep your router from tearing >> down BGP sessions when it finds a loop. Don't forget to commit >> afterwards, and then to do a "save config config" so it will take after >> you reboot. > >This wasn't a loop. This was a malformed AS path. The length of the >entire AS Path attribute was 14 bytes, and the length of the first AS >Sequence segment was 7 AS's, even though there wasn't room to fit that >many in 14 bytes. (7AS's * 2 bytes each + 2 bytes for the segment >header, gives a minimum of 16 bytes needed.) > >Does this attribute also disable detection of malformed AS Paths? No. -- George > > - Brett ([email protected]) > >--------------------------------------------------------------------------- --- > ... Coming soon to a | Brett Frankenberger >.sig near you ... a Humorous Quote ... | [email protected] > >
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