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OSPF different process id and BGP

Dayat_Azchew
Level 1
Level 1

Hi All,

Please find the attached for network topology.

I've a problem with ospf routing protocol. If i'm use bgp everything running as well, no issue.

But when bgp was down at branch office, ospf is not working normally. Can't reach to Internet and Server to Vendor.

Example : from network 172.30.128.128/26 can reach to 172.22.0.0/20 but can't connect to internet and vendor 149.122.25.0/24

Please advice, how the correct configuration if i'm use ospf different process id and bgp.

Thank you

Regards

7 Replies 7

Leonardo Gama
Level 1
Level 1

Hi Dayat,

Are you doing mutual redistribution at HQ between OSPF and BGP?

Cheers.

Dear Leonardo,

I'm redistribute ospf into bgp and vice versa at HQ router.

Here are the configuration.

Redistribute bgp into ospf.

router ospf 10
 router-id 172.22.12.14
 redistribute connected metric 10 subnets
 redistribute bgp 65432 metric 10 metric-type 1 subnets route-map REJECT_BGP-OSPF
 redistribute ospf 50 subnets
 passive-interface default
 no passive-interface Port-channel1.201
 network 172.22.12.0 0.0.0.15 area 0

default-information originate
!
router ospf 50
 redistribute ospf 10 subnets
 network 1.2.47.0 0.0.0.7 area 20

default-information originate


!

Redistribute ospf to BGP

redistribute ospf 10 metric 10000
 redistribute ospf 50 metric 10000

Hi Dayat,

I don't see BGP redistribution under OSPF process-id 50. Is it a typo?

Also, can you provide LSA 5 output from show ip ospf database of Branch office router?

Regards,

Interesting configuration.

Why is it necessary to run two OSPF processes? Especially since you are redistributing between the two. Why not run it as a single process?

Also, if with the Internet down at the branch site, trace routes to the Internet and server show only the first hop, which I assume is HQ, then chances are the next hop after HQ doesn't have the routes back. This would indicate that HQ may no longer be advertising the branch office network to them. That would be something to check.

It may be more involved than just that, but again, running a single OSPF process may rectify the situation.

With BGP down specific routes for the ISP or to the Server network, and probably also the default route, would not be distributed into the OSPF.  

Internal routes would be present as part of the OSPF so the branch router would know how to get to HQ, but would have no way of knowing where to send traffic for the external sites.  

Hello

What does a traceroute show from branch rtr

Do you have access to the HQ rtr -  if so can you trace from there and from a source interface towards IVPN2
what does the route tables show for that branch subnet on HQ rtr

res
Paul


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Kind Regards
Paul

Hi Paul,

If i'm trace from HQ to branch, trace result complete. and vice versa.

But if I'm trace from branch to internet and server, only 1 hope to router. and ping result destination host unreachable.

Thank you

Regards

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