05-07-2008 03:03 AM - edited 03-05-2019 10:48 PM
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?
Solved! Go to Solution.
05-07-2008 06:04 PM
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,
05-07-2008 03:28 AM
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
05-07-2008 06:04 PM
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,
05-07-2008 06:20 PM
Hi all,
Thannks HAROLD, I missed that one.
Cheers
Thot
05-07-2008 07:17 PM
Yes, the problem was in "capability vrf-lite".
Thank you guys!
You're doing great job!
08-19-2013 01:44 PM
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
08-19-2013 05:09 PM
Hi Julio,
You are very welcome. Interesting blog.
Regards
09-22-2018 01:39 PM
Kudos Harold
A sort of caveat in ospf that I think is misunderstood or misinterpreted regards its default loop prevention.
09-22-2018 07:30 AM
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.
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