[c-nsp] Load balancing outbound traffic with BGP

[Jeff Chan]

Hi All,
Given multiple, roughly equal upstreams (Sprint, ATT, Level3)  
providing full BGP tables to a small ISP, what's the best way to  
balance the outbound traffic?  The problem is that all else being  
equal (path length, local pref, etc.) BGP decides to take the one with  
the lowest peering IP address.  Given that the upstreams have  
many/most of the same customers and peers, the peer with the lowest IP  
address seems to win too often, meaning it does too much outbound  
compared to the others.

I asked the same question some time ago and the common practice answer  
seemed to be prefer traffic for some other large networks (UUNet,  
Qwest, AOL, etc.) over the peers with higher IP address.  Is this  
still the case?  Seems kind of an ugly hack, but it works.

Are there any other approaches?  How about jumbling up or staggering  
the local preferences:

ISP S:

customers: localpref 120
peers:     localpref 110
others:    localpref 100

ISP A:

customers: localpref 110
peers:     localpref 100
others:    localpref  90

ISP L:

customers: localpref 100
peers:     localpref  90
others:    localpref  80

Where S has the highest IP address, A next highest, L lowest.  Haven't  
tried this; just a thought to try to compensate for the IP address  
decision.

Cheers,

Jeff C.