BGP multihoming question.

Fri Dec 10 15:01:37 UTC 2010

Our organization does exactly this. The requirements we have run into are:

1. The block needs to be at least a /24 and registered with SWIP
2. You will need LOAs from the owner of the block. This used to take months to get, now it seems the isps have streamlined this operation
3. You cannot trust the second isp to advertise the SWIP block correctly if they are not a tier 1. Even though they may advertise it for you to their upstream, they don't always have the appropriate procedures in place to get the LOAs to the upstream so your block just gets filtered out. 

Dylan Ebner

-----Original Message-----
From: b2 [mailto:b2 at playtime.bg] 
Sent: Thursday, December 09, 2010 5:32 AM
To: North American Network Operators Group
Subject: BGP multihoming question.

Hi , first sorry for lame question but i'm new to BGP.
In my ISP I have two full BGP sessions with my two transit providers (X and Y), and for every provider i have assigned PA (Provider
Aggregatable) networks. Is it possible (if there are no filters on other
side) to advertise X networks to Y and Y to accept them ? My confusion comes from the PA status , i know if it is PI there are no problem to route it to any AS. 
Thanks.