Receiving routes with own AS?

[Timo Schoeler]

On 06/24/2012 10:36 PM, Tom van Leeuwen wrote:
> That sounds very logical. The only way around this is iBGP or a new
> AS number?

Cisco-speak is 'allow-as in' for this. I don't know if they use some
more sophisticated logic to prevent loops, though. What I did see during
the last months was that OpenBSD's bgpd also didn't (or still doesn't?)
provide this feature, but can be patched. People asked for it (no link
handy right now). quagga also supports it, so there is source code
available to see how to tweak bird, I guess.

HTH,

Timo

> ~tvl
>
> On 06/24/2012 09:59 PM, Martin Kraus wrote:
>> 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