- Purple, 4500 points or more
I'm having a hard time understanding something.
If I have a router that is an ASBR and an ABR that lies on area 0 and NSSA area 1. This router is redistributing EIGRP 100 into OSPF. The router in area 1 is seeing the redistributed route as an N2 route.
I have another router in the same topology configured the same way and is redistributing its routes into area 0. I don't see these routes on the area 1 router.
I know that NSSAs only allow type 7s into their areas, and these are converted by the ASBR. I also *think* that type 5s aren't allowed into NSSAs because they're considered a stub area.
So, my question is why is the router that's an ASBR and ABR advertising it's EIGRP route to the NSSA area, but the other router isn't seeing it?
NSSA areas have been introduced to allow routers in a stub routers to inject = accept external routes.
These routes are injected as O N2 or O N1 by NSSA ASBR and can be converted by NSSA ABR(s) in normal O E1, O E2 routes to be propagated in the OSPF domain in backbone and normal areas.
For this reason an O E2 route generated by top router is not allowed in the NSSA area.
What you see is correct: middle router plays the double role of ABR (NSSA,0) and of ASBR so it is allowed to inject the routes that are locally redistributed as O Nx routes but it can never take from the backbone database an O Ey route to inject it into the NSSA area database.
In other words the translation works only on the opposite direction from NSSA area to backbone area.
Hope to help