BGP Options to Reduce Failover and Reconvergence times

[AJAZ NAWAZ]

Platform 65k SUP2-T / 10Gig P 

R1--iBGP--R2 <====eBGP====> R3---iBGP---R4

R2 and R3 linked over 10Gig ethernet type circuit - DC interconnect.

I'm currently advising a client on doing away with its IGP, OSPF. The organisation changes fairly constantly and OSPF doesn't help with its lacking capabilities in the filtering department, and even more than that, one often ends up with heaps of bewildering redistribution. Fortunately the org is not mission-critical happily accepting 30-60sec failover.

The overarching topology is simple and total number of prefixes currently stands at less <100.

So we're doing away with OSPF, but what I wanted to please ask was how much tuning is now available for eBGP and iBGP, I mean in terms of fast-failover whats' the quickest I can get these peering to failover / reconverge

Thank you

[Mark Malone]

There is a few options but you need to be careful tweaking bgp timers , you also have the scan time and couple of other options , I would start decreasing them bit by bit if its a necessity and then monitor the network before increasing them again, bgp was not built for fast convergence so you will only get so far

take a look at this link explains a couple of them

http://networkgeekstuff.com/networking/cisco-bgp-timers-re-explained/