Hi Bill, Could you list which prefix(es) you saw were being announced with these long AS paths? Mark On Sat, Sep 30, 2017 at 6:29 PM, William Herrin <bill@herrin.us> wrote:
To the chucklehead who started announcing a 2200+ byte AS path yesterday around 18:27 EDT, I beg of you: STOP. You've triggered a bug in Quagga that's present in all versions released in the last decade. Your announcement causes routers based on Quagga to send a malformed update to their neighbors, collapsing the entire BGP session. Every 30 seconds or so.
For everyone else: please consider filtering BGP announcements with stupidly long AS paths. There's no need nor excuse for them to be present in the DFZ and you could have saved me a painful Saturday.
Cisco:
router bgp XXX bgp maxas-limit 50
Juniper: https://kb.juniper.net/InfoCenter/index?page=content&id=KB29321
Quagga:
ip as-path access-list maxas-limit50 deny ^([{},0-9]+ ){50} ip as-path access-list maxas-limit50 permit .*
Regards, Bill Herrin
-- William Herrin ................ herrin@dirtside.com bill@herrin.us Dirtside Systems ......... Web: <http://www.dirtside.com/>