iBGP usage on a BRAS

Tue Mar 29 12:08:39 UTC 2011

Hi Mike,

iBGP is what most ISPs would use for that, for customers with dynamic IPs simply aggregate their addresses on the BRAS, if you have several thousand IPs you really don't want them in your IGP

Regards,
Ido. 

-----Original Message-----
From: Mike [mailto:mike-nanog at tiedyenetworks.com] 
Sent: Monday, March 28, 2011 11:58 PM
To: NANOG list
Subject: iBGP usage on a BRAS

Hello,

	I have a BRAS (Terminating several thousand PPPoE sessions), and today I use simple static routes pointing to the bras for customer routes. I want to improve this model and allow for failover and so forth, and I would like instead for my customer routes to be entered into my igp so if they move around, the routes can follow them. I was wondering if iBGP may be sutaible for this task - there will always be a steady stream of route updates as customer connect and disconnect, mostly in the range of /32's and /29's. BGP seems way superior to ospf for this because of it's excellent filtering and other capabilities, but never having done this on a large scale with the potential for updates as I said, I was hoping someone could make a clear case for or against it.

	The client routes would not have to be propagated all across my network so updates don't really have to go far; I could certainly summarize these routes easily at a core router 1 hop from my bras for example, with that router(s) knowing the final hop from ibgp. I just want them to be able to float between bras and I can even tolerate a few seconds of route instability (hey, if you want stability then don't keep redialing; nail the pppoe up and leave it up!)

Thank you Oh wizend ones (!),

Mike-