[nsp] BGP Q

Bruce Pinsky bep at whack.org
Mon Feb 9 17:40:40 EST 2004

Hash: SHA1

Beprojects.com wrote:

| Here's a dumb BGP question to which I cannot fnd an answer.
| Let's say you connect to two upstream ISP's, Sprint (for example) and ABC
| Corp.  Obviously, because of the difference in size, almost all of the
| traffic will enter and exit Sprint.  For incoming traffic, you can pre-pend
| your AS to advertisements out the Sprint link so that the path in via ABC
| and Sprint are roughly equal.  This does a pretty good job of evening up
| traffic.  The question is "can this be done on BGP advertisements that I
| receive?"  I want to pre-pend an AS to the advertisements I receive from
| Sprint so that they look longer than they really are in hopes that some
| traffic will go out ABC's link.  Or is there another way to do this?  I
| don't want to use weight or preference as I don't want to force all traffic
| out ABC, just some.
| And I don't want to discuss the merit's of buying from a big ISP and a small
| ISP, etc.  I just have a question of whether it is possible.  Thanks.

You can apply weights or local preference to just some of the routes
learned from your providers.  You could analyze the traffic distribution to
various prefixes and then local preference to balance out the load.

There are also a number of products in the Route Optimization space that
will do this for you automatically.  See folks like Proficient Networks and

- --

Version: GnuPG v1.2.2 (MingW32)


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