On Mon, Jun 10, 2013 at 9:43 AM, Joe Abley <jabley@hopcount.ca> wrote:
On 2013-06-10, at 18:36, "Dennis Burgess" <dmburgess@linktechs.net> wrote:
I have a network that has three peers, two are at one site and the third is geographically diverse, and there is NO connection between the two separate networks.
Currently we are announcing several /24s out one network and other /24s out the second network, they do not overlap. To the internet this works fine, however, providers a/b at site1 do not send us the two /24s from site b.. We have requested them to, but have not seen them come in, nor do we have any filters that would prohibit them from coming in.
Is this normal?
Yeah.
Can we receive those routes even though they are from our own AS?
You can stop them from being suppressed inbound by using "neigh x.x.x.x allowas-in" on a cisco, or "set neigh x.x.x.x allowas-in" on JunOS.
What is the "best practice" in this case?
I don't know. Above seems reasonable. I've seen people join their sites with tunnels plumbed to router loopbacks in different sites and run IGPs over them before; this gives them inter-site connectivity which makes the question moot. But it involves tunnels.
Joe
If your upstream provider runs JunOS, they may not be aware that their gear won't send you the routes by default, no matter what their policy says: "The JUNOS software does not advertise the routes learned from one external BGP (EBGP) peer back to the same EBGP peer. In addition, the software does not advertise those routes back to any EBGP peers that are in the same AS as the originating peer, regardless of the routing instance. You can modify this behavior by including the advertise-peer-as statement in the configuration." (from http://www.juniper.net/techpubs/software/junos/junos95/swconfig-routing/id-1... So, you may need to help walk them through adding the "advertise-peer-as" flag to your neighbor configurations if they use Juniper kit. Matt