On Wed, 3 Oct 2012, Joseph Jackson wrote:
I have cacti graph the amount of prefixes announced and withdrawn from a BGP peer on each BGP router.
+1 Note that not all router OSs support fetching data like that via SNMP. We use a custom built thing internally that does this two, which we then tack on an alert threshold for. So if a downstream peer sends us less than that, we get an alert. Handy for those times when they call and ask us what we did to their network. :-) Prior to that, we had a script which whould login, munge the 'show ip bgp summary' table output, figure out the deltas and graph or report as needed on a particularly troublesome peer.
-----Original Message----- From: ML [mailto:ml@kenweb.org] Sent: Tuesday, October 02, 2012 11:43 PM To: North American Networking and Offtopic Gripes List Subject: Internet routing table "completeness" monitoring?
Has anyone put in place a method to identify if one their BGP peers suddenly withdraws X% of their prefixes?
e.g I should expect ~420k prefixes in a "complete"[1] routing table from a transit peer today. If suddenly I'm only getting 390k prefixes I'd guess a major network was depeered or similiar.
If so how are people doing this? SNMP MIB, screen scrape?
[1] Varying levels of completeless apply.
wfms