Show IP Route in HUB-Spoke setup

[karamalomari]

I have a question regarding OSPF point-multipoint non-broadcast setup. The links between Hub's & spokes are private links.

attached is the drawing with configuration files of Site-A with wan router-FW-Core Switch & Site-B with wan router-core switch.

The question is when typing

 #sh ip route | inc 192.168. on Hub-01 i see it as O E2 and #sh ip route | inc 172.16. on Hub-01 i see it as O IA

is this the correct ospf route i should see.

[David Ruess · Accepted solution]

Hello,

Yes this is exactly what it supposed to look like. With OSPF the network type that shows up is how it was introduced/sent into the network.

On Site A and Site B you have your separate areas. If nothing else was configured they would both show up as O IA routes in your area 0 as they are Inter-Area routes.

However note one key difference - on Site A you have the 

redistribute static subnets 

command. This changes the route type and turns it into a Type 5 or 

External O E2 

route by default. 

You are doing redistribute static with the static route to the 192.168.0.0 network configured at Site A. On site B you have no redistribution so you see regular O IA routes.

Hope that helps

-David

[karamalomari]

Dear David,

couple more questions related to the same topic.

If I use a route-map and redistribute the route-map, route will still show as External O E2?

If I use only redistribute static, route will still show as External O E2?

[David Ruess]

Yes it will. Redistribution of anything static, anything in a route map, another routing protocol will make the route O E2 because it’s a type 5 LSA. That’s how it’s categorized. You can tack on a command metric-type 1 when you redistribute to change it to a type 1 - O E1 route. 
The only way to have it show up as an O IA route is to use the network command or enable OSPF directly on the interface with the ip ospf # area x command.

-David

[MHM Cisco World]

I need to see the tunnel config 
can you share it ?

[karamalomari]

There is no tunnel configuration, this is direct connection (Point-2-Multipoint).

The configuration on the Service Provider is not feasible to us.

[MHM Cisco World]

I will run lab to see the what exact happened. 
I dont think it relate to redistribute static, but let me check first.  

[MHM Cisco World]

int g0/3
ip address 192.168.254.6 255.255.255.252
!
router ospf 1
area 192 stub no-summary
area 192 range 192.168.0.0 255.255.0.0
network 192.168.0.0 0.0.255.255 area 192
network 192.253.100.192 0.0.0.255 area 0
network 192.253.200.192 0.0.0.255 area 0
redistribute static subnets
!
ip route 192.168.0.0 255.255.0.0 192.168.254.5

I run small lab (not exact IP subnet but same topology), 
now return to your network 
area 192 range 192.168.0.0 255.255.0.0 <<- this must advertise the 192.168.0.0/16 to Hub1+Hub2
and then advertise static route, but why static route is advertise and the O IA is not advertise??
 the answer for this Q is the 192.168.254.0 <<- this prefix is missing in OSPF database and hence the range is not advertise and static route is advertise. 

so check ip ospf database for 192.168.254.0/30 <<-  

[karamalomari]

The topology that I have is little different that the one you have in site-A I have RTR-->FW-->CSW and site-B RTR-->CSW

In site-A i have updated the router ospf section as:

router ospf 1
area 192 stub no-summary
area 192 range 192.168.0.0 255.255.0.0
network 192.168.0.0 0.0.255.255 area 192
network 192.168.254.0 0.0.0.3 area 192
network 192.168.254.4 0.0.0.3 area 0
network 192.253.100.192 0.0.0.255 area 0
network 192.253.200.192 0.0.0.255 area 0
redistribute static subnets
!
ip route 192.168.0.0 255.255.0.0 192.168.254.5
!

After that I have tried checking for the 192.168.254.0/30 in the Site-A OSPF Database after adding it, but still it was not showing in the database.

Then, I have added the this static route: ip route 192.168.254.0 255.255.255.252 192.168.254.5

Checking the OSPF database it shows: 192.168.254.0 192.168.254.5.

Now, checking the routes on HUB-1&2

#show ip route | inc 192.168.
O E2   192.168.0.0/16

O E2   192.168.254.0/30

O        192.168.254.4/30

[David Ruess]

The reason you and @MHM Cisco World cannot see the routes for the redistributed static is because your OSPF area is a stub. By definition a STUB blocks Type 4 + 5 LSA which is given to a route redistributed into OSPF and it makes it an O E2 route - adding the no-summary it also blocks type 3 (which is the summary LSA). If you want to apply redistribution in that area you would need to do an NSSA area not a stub.

-David