Received routes over BGP with wrong interface

[RaniGome]

Hello everyone!

I'm having some problems to redistribute bgp routes learned from another part of the network. The routes learned Hub to hub works fine on the hubs, however in the spokes, the routes learned from the other part are pointing to WAN interfaces, not the overlays. 

I've created the topology inside GNS3 to test pre-production:

I'm using the same AS with iBGP and next-hop-self-rr on the hub to hub overlay neighbor configuration. 

Hub routing table:

Spoke routing table:

Any ideas?

[knaveenkumar]

Hi 

1. Please check the routes for the next -hop ip 10.200.1.254 , how it is learning.

2. Also, can you please run the below command in the spoke and provide the output.

get router info routing-table x.x.x.x

x.x.x.x destination network 

3. config router bgp

sh 

4. From which routing protocol to which protocol, you are doing redistribution.

[RaniGome · Accepted solution]

Hi

I checked some information on the lab and I figured out why it was not working. The advertisement of the routes were correct, I'm using "set next-hop-self-rr enable" on the hub x hub tunnels. However, the relationship of the BGP route and the interface that will be used to that route is done in FortiOS. After I created the static routes to the overlays networks, everything worked fine.

[Sowie]

Hi Rani 

I seem to be having the same issue that you were having but I don't fully understand your solution. Please have a look at my post if you have time.
https://community.fortinet.com/t5/Support-Forum/Redistribute-OSPF-over-BGP-Between-to-FotiGates-wron...

[RaniGome]

Hi Sowie

In my case I redistribute BGP routes from another side of the network, I changed the AS of Hub2 and it spokes to a diferent number, using BGP neighbot groups to configure BGP inside hub and spokes from the same hub. the comunication from hub to the another hub I'm using another overlays and BGP neighbor configuration, to not mess up with internal hub routes. 

The configuration  "set next-hop-self-rr enable"(https://community.fortinet.com/t5/FortiGate/Technical-Tip-How-to-modify-BGP-next-hop-for-route-refle...) is used to make the hub from it side of the network redistribute the routers with the address from itself as the source to the spokes of it side. 

I'll look for a kb and post to try to solve your problem with OSPF redistribuition. You have to consider the concept of BGP propagate prefixes and OSPF propagate networks and interfaces with LSA. I'm no BGP or OSPF specialist, Fortinet provides a very good documentation about them.