OSPF external route cant be installed in routing table

[Majid Jalinousi]

Hi buddies,

I've an issue with OSPF external routes and I cant understand why the routes cant be installed on the routing table.

The topology of the network is like below:

R1(10.1.1.2) -> (10.1.1.2)R2(10.1.2.2) -> (10.1.2.3)R3

So a OSPF routing protocol between R1 and R2 is running and they are neighbors on the area 0. between R2 and R3 there is no OSPF neighbor-ship but OSPF is enabled on the interface connected to R3 and R2 will learn all the subnets behind R3 through static route and redistribute them on the OSPF domain.

On R1 I have OSPF external routes for subnets redistributed to OSPF domain with forward address of 10.1.2.3. Although I have an intra ospf route for this forward address on the routing table of R1, the external routes redistributed on to the OSPF with this forward address cant be installed on the routing table of R1. what would be prevent for installing these external routes?

I would be so appreciate for any help.

BR.

[Majid Jalinousi]

Hello, 

R1 and R2  is connected to each other on area 0, then all the static routes redistributed in backbone area and on R1 I have them as external route type 2 "E2". 

I can see these routes on the OSPF database with command "show ip ospf database external".

Actually at our practical network these two routers are also neighbors on several other totally nssa areas, then R2 also has all these redistribted routes with nssa external "N2".

As I know if the forward address of E2 routes has been learned by the router through intra or inter area route, then these E2 routes are able to be installed on the routing table, but here it doesn't work and you think restarting the router may help, right? 

Thanks

BR, 

[Harold Ritter]

Hi Majid,

Since the interface between R2 and R3 is only being used as a passive interface, why don't you configure it as passive with the "passive-interface <interface-name>" under OSPF. This will cause the forwarding-address to be set to zero and the route should then be installed.

Regards,