Dear All
I am peering with two different ISPs, ISP A and ISP B, and receive a full
routing table from both of them. Let's assume they are both connected
to the same router.
There is obviously a need to load-balance outgoing traffic between these
two ISPs. I would like the deciding factor to be AS_PATH length, i.e.
prefixes advertised with a shorter AS_PATH by ISP A than by ISP B would
be reachable through ISP A (and vice versa), while prefixes with an equal
AS_PATH length would be always preferred through ISP B.
To achieve this I set the MED on updates coming from ISP A to 20 and from
ISP B to 10 and configured 'bgp always-compare-med' on the router.
Now to my questions:
1. Is there something wrong with the above scheme?
2. What are possible caveats in using 'bgp always-compare-med'?
3. Are there other ways to implement this?
4. What other ways to load-balance outbound traffic are there?
The ones I know about are:
- do nothing
- partial table from A, full from B
- A and A's customers through A, rest to B
- ...and similar ones...
I appreciate your comments on this subject.
Regards,
Elijah Kagan
This archive was generated by hypermail 2b29 : Sun Aug 04 2002 - 04:12:21 EDT