Dual Homed BGP for failover

Wed Jan 19 14:26:32 UTC 2011

We're doing BGP to announce our PI space and make sure that our PI space is
reachable through both ISPs in case one link goes down.  This is the primary
need to do the BGP here.  Unfortunately my boss has requested that we make
use of the capacity of both links, rather than pref traffic out of the
higher capacity link.

-----Original Message-----
From: Randy McAnally [mailto:rsm at fast-serv.com] 
Sent: 19 January 2011 14:00
To: Ahmed Yousuf; 'nanog group'
Subject: RE: Dual Homed BGP for failover

On Wed, 19 Jan 2011 10:23:47 -0000, Ahmed Yousuf wrote

> -          Accept that we are never going to get an ideal 
> distribution of traffic and continue monitoring and adjusting local 
> pref/prepends etc. as and when we need to change the distribution of 
> traffic.  Hopefully we don't need to do this that often.

^ This.  You're fighting a loosing battle with such slow links.  Given the
limited route capacity of your router you might as well set up statics aimed
at each link and forget about BGP shaping.  Just keep a floating default
pointed at each peer.

-Randy