OSPF inter-area routes are not installed in VRF routing table

[tcherkon]

Hello!

I have a simple topology: two routers R1 and R2 connected to each other through ethernet link. Both routers runs OSPF. R1 runs OSPF process in the VRF 1. The ethernet link is configured for OSPF area 4. R2 also have loopback interface in area 0. Now when I look for ip routes in VRF1 in R1 I doesn't see route for R2's loopback 0. But when I look in OSPF database I see that summary LSA for this network is present. It seems that R1 doesn't install this route in VRF's routing table. Here are routers' configs:

R1:

ip vrf 1

rd 1:1

interface Ethernet0/0

ip vrf forwarding 1

ip address 10.0.0.1 255.255.255.252

router ospf 1 vrf 1

network 10.0.0.1 0.0.0.0 area 4

R2:

interface Loopback0

ip address 192.168.0.2 255.255.255.255

!

interface Ethernet0/0

ip address 10.0.0.2 255.255.255.252

router ospf 1

log-adjacency-changes

network 10.0.0.2 0.0.0.0 area 4

network 192.168.0.2 0.0.0.0 area 0

Show commands on R1:

R1#sh ip route vrf 1

10.0.0.0/30 is subnetted, 1 subnets

C 10.0.0.0 is directly connected, Ethernet0/0

R1#sh ip ospf database

...

Summary Net Link States (Area 4)

Link ID ADV Router Age Seq# Checksum

192.168.0.2 192.168.0.2 144 0x80000002 0x00B3B0

Why this LSA is not installed in the routing table?

[Thotsaphon Lueangwattanaphong]

Hi KONSTANTIN,

please do as follows:

R2:

interface Loopback0

ip vrf forwarding 1

ip address 192.168.0.2 255.255.255.255

interface Ethernet0/0

ip vrf forwarding 1

ip address 10.0.0.2 255.255.255.252

Keep that in mind: You need to apply the L3 interface into the VRF you want!

Hopes this helps

Thot

[Harold Ritter · Accepted solution]

Konstantin,

Summary LSAs are not installed by default in a VRF-lite context. You need to use the following command on R1 to change this behavior.

router ospf 1 vrf1

capability vrf-lite

This should fix the issue.

Regards,

[Thotsaphon Lueangwattanaphong]

Hi all,

Thannks HAROLD, I missed that one.

Cheers

Thot

[tcherkon]

Yes, the problem was in "capability vrf-lite".

Thank you guys!

You're doing great job!

[Julio Carvajal]

Harold,

Thanks for this answer Just what I was looking for. Kudos to u

Check my blog at http:laguiadelnetworking.com for further information.

Cheers,

Julio Carvajal Segura

[Harold Ritter]

Hi Julio,

You are very welcome. Interesting blog.

Regards

[paul driver]

Kudos Harold

A sort of caveat in ospf  that I think is misunderstood or misinterpreted regards its default loop prevention.

[andrius.vainauskas]

The OSPF VRF process acts as an Area Border Router (ABR) when configured without the capability vrf-lite. This means that it will not examine summary-LSAs if they come via non-backbone area.