[c-nsp] Readvertising strangeness.

[Gustav Ulander]

Hello people.

I have some strange things going on here.
Iam doing  some test configurations in the lab and are trying to see how 2 AS numbers behave when they peer via their respective route reflectors.
I am using CSR1000v for this lab as a start.
I have 2 AS numbers to start with. Every AS has 1 PE router, 1 P router and 1 route reflector.
The PE and RR are doing IBGP and MPLS. The P router is doing IGP (OSPF) and MPLS. The 2 AS numbers are connected via IGP between P routers.
The two route reflectors are doing EBGP between themselves with next-hop unchanged to allow the PE routers to send traffic directly towards each other.
Everything Is working as expected and Iam able to import and export route targets across ASes when I have locally attached interfaces.
The strange part arises when I add EBGP links to the PE routers.
I can have a VRF that has a loopback in each PE router ping works perfectly between them and traceroute says that iam using the label switched path via P routers.
However If I introduce a EBGP link in the VRF the router that has the link can no longer ping the other PE router. The PE router that dosent have the link can ping the first PE router.
So it seems that when I introduce a EBGP link in the vrf the forwarding stops working.
The routes from the other is still in the table and labels are assigned and so forth. Anyone have any input?


//Gustav