Internet routing table "completeness" monitoring?

Saku Ytti saku at
Wed Oct 3 06:52:25 UTC 2012

On (2012-10-03 00:43 -0400), ML wrote:

> Has anyone put in place a method to identify if one their BGP peers
> suddenly withdraws X% of their prefixes?

I've had monitoring for this for many years, over SNMP. Right now my limits

a) prefix count went or came from 0
b) relative difference is minimum 1.5x and absolute difference is minimum of 1000

Output what I get as emails:
rtr1: AS702 2001:600:202::15 ge-1-0-4.BR2.LND18.ALTER.NET 0 => 34
rtr2: AS2119 688 => 0 (1/3)
rtr2: AS2119 2001:4600:10::4d 13 => 0 (2/3)
rtr3: AS3491 37548 => 4710

And there are about 10-20 emails per day, even when looking only rather
'coarse' changes. 

But to be honest, I almost never peek at the folder where I get these, I'm
probably moving the output on IRC channel, as I've found it superior way to
keep track of alarms compared to emails for my workflow. 


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