dual peer ebgp

mmark751969 · Guest

i have a 7206 configuration that is running ebgp. This happens to be
running ebgp between 2 peers within the same isp however(same remote-
as number. Both of the peers have different ip addresses though).
This isp is handing us a 100mb ethernet connection over fiber. Just
wondering if it is accepted practice to be running ebgp this way
instead of having the peers at different isp's.

p_teatreeoil · Guest

There are some advantages to being dual homed. You can be more
granular with your prefixes since your ISP will accept ones that are
longer than 24 bits (this is useful if your connections terminate on
different PE routers). Or, if your links both terminate on the same
PE router, you can load balance your traffic with multipath. Being
dual-homed to the same ISP is a lot less complicated than being multi-
homed, but you give up the advantage of being able to optimize based
on peering diversity between different ISPs.

Your situation is not unique and there is nothing wrong with doing it
that way; you're still getting at least some redundancy and it's a lot
easier to get started with one ISP. If and when you decide to move
on to ISP diversity, you'll want to be sure to familiarize yourself
with each ISP's BGP Policy and how they treat routes from their BGP
customers versus peer ISPs. Also, if you don't have your own ASN,
you'll have to get one through ARIN. You'll also have to consider
whether you want to load balance, which is not an exact science across
multiple ISPs, or if you will be using one connection as a pure
backup.

Lotsa stuff to think about if you're going to be multi-homed.