Re: eBGP, iBGP, injecting networks

["Ing. Hans L. Reyes" <ludwing () internet2 unam mx>]

Hi

Your problem may be is similar when one ISP buy to another ISP, sometimes
is easy to modify the IGP like in this case (OSPF) because it is something
inside of your company and you have the control over all the devices but
you still have the problem outside of the company; client, others ISP, etc

Check the feature of BGP "Local-AS" for routers Cisco if yours routers
aren't Cisco, check for someone similar with your vendor. May be you need
to do something else.

This is the url where explain how it works.

http://www.cisco.com/en/US/tech/tk365/tk80/technologies_configuration_example09186a00800949cd.shtml

I hope it help you
-Hans

On Fri, 20 Feb 2004 isaac () ravengate net wrote:

> greetings list,
>
> hoping someone can hook me up on the right way to do this.    
>
> ---
>
> we have two ASN's we control.
>
> we have two border/edge routers (1 in each ASN) that talks to a
> different backbone provider.
>
> the two border routers peer with eachother over eBGP and also are in
> the same OSPF process.  (we are working to merge them into the same
> BGP ASN)
>
> my question is this:
>
> how do we achieve router redundancy between these two routers?
>
> currently if we lose a transit link, the traffic will flow fine out
> the other pipe.
>
> but we don't have BGP network statements in router 2 that exist in
> router 1 and we don't have BGP network statements in router 1 that
> exist in router 2.
>
> so the routes injected into BGP from router 1 will get withdrawn right
> if router 1 dies?
>
> is it a problem to announce the same networks from two different eBGP
> peers to two different upstreams?
>
> ------
>
> if you are still reading, thanks!
>
> to clearify some more-
>
> current setup:
>
> current setup:
>
> ASN 1 (we're not Genu!ty- just using for an example)
>
> :)
>
> ASN 1 injects all of its own space and announces this space to
> Above.net and ASN 2
>
> ASN 2 injects all of its own space and announces this space to Savvis
> and ASN 1.
>
> so stuff out on the net looks like:
>
> 1 6461 etc etc
>
> and
>
> 1 2 6347
>
> -------
>
> 2 6347 etc etc
>
> and
>
> 2 1 6461 etc etc
>
> -------
>
> so, you see we are prepending on of our AS's on the way out.
>
> the problem is tho, we only have 1 router in each respective Autonmous
> System injecting address space.  if we lose that router, we lose
> announcing that ASN's space.
>
> is it totally going to cause probs to have routes originating from two
> different AS's?  routing loops would be a real drag.
>
> what about having an iBGP router in AS 1 inject the same space as the
> border router in AS 1?  this other router also peers with AS 2....
>
> thanks a lot!
> jg