Receiving routes with own AS?

[Martin Kraus]

On Sun, Jun 24, 2012 at 07:17:58PM +0200, Tom van Leeuwen wrote:
> Hi guys,
> 
> We have a new location and have installed a bgp server with bird.
> We are already using our AS and bird at the main site, but want to
> use that one as well on the second site.
> 
> I'm not sure if I want/need to run iBGP, but if I had and the link
> would fail, I should have at least a route through IPT to our main
> site.
> 
> I'm already connected through IPT at our new site, but I'm not
> getting any routes for our subnets that are being announced at our
> main site. Our upstream provider says that they are not filtering
> the routes and that it should be my configuration that is filtering
> them. Well, I have 'import all' so that should not be the problem.
> Does bird have some built in logic that does not accept routes with
> my own AS? Or is the IPT incorrect?

BGP filters out routes which have it's AS in the AS path as a loop prevention.
This is a feature of BGP. 

mk