Hello Sundar,

If i put " redistribute static subnet" under ospf. You think it will get propogated under ospf.

You see on Montreal i have a IBGP connection to Alaska router. On Alaska router i am getting it fine through IBGP. but it has the same OSPF configuration as Montreal. Even though Static is on Montreal shouldn't Alaska router send it to OSPF network.

Will appreciate your input.

Thanks,

Hassan

Hassan,

See the responses below.

"If i put " redistribute static subnet" under ospf. You think it will get propogated under ospf."

Yes. Optionally, you can use a route-map with this configuration to ensure only the static routes that you desire get advertised via OSPF.

"You see on Montreal i have a IBGP connection to Alaska router. On Alaska router i am getting it fine through IBGP. but it has the same OSPF configuration as Montreal. Even though Static is on Montreal shouldn't Alaska router send it to OSPF network"

I don't understand your topology fully. But, if Alaska is learning the route via BGP and if you are redistributing BGP into OSPF on Alaska router then the routers that are talking OSPF with Alaska router should indeed learn the route via OSPF. We need to look at Alaska router configuration in full to give you definite answers.

HTH

Sundar

Hassan,

The reason Alaska doesn't redistribute the route to OSPF is that iBGP routes are not redistributed into the IGP by default. This default can be changed by using the "bgp redistribute-internal" command under router bgp. You need to be careful with that command though.

My preference would be to use "redistribute static" under router ospf on Montreal.

Hope this helps.

Hello,

Guys, thanks for all your response..i will copy the config. to be more clear.

But what i have understood is on Montreal router under ospf i need to have " redistribute static metric-type 1 subnets". This will inject my static route to OSPF.

Another point Hritter brought up is IBGP learned route on Alaska for 165.162.240.24/29 which is statically configured on Montreal will not be send to OSPF from Alaska. Correct me if i am wrong. I wil paste the config. to be more clear.

My ass is on the Sling here. Because i am redistributing routes from BGP to OSPF and then OSPF is also redistributing routes into BGP. so it's one big happy redistribution going on. There are some core components which needs access to BGP environment and also some core components sitting in BGP which needs access to OSPF ( that's why this crazy redistribution both ways).

Hassan,

Your understanding, that 165.162.240.24/29 is not redistributed from BGP to OSPF on Alaska because it is received as an iBGP route, is correct.

Regards,

Your understanding is correct for the most part. Just redistribute static into OSPF on Montreal router and that should solve your problem. I just would add that anytime you do mutual redistribution between routing protocols be careful with route feedback, i.e a route that's native to one protocol getting advertised back into it by the protocol into which it was redistributed originally. Use route maps to ensure to eliminate route feedback situation. As far as hritter's comment about the 'bgp redistribute-internal' command see the Cisco FAQ below.

Q. How can I redistribute internal BGP (iBGP) learned default-route (0.0.0.0/0) route into EIGRP/OSPF/IS-IS?

A. The redistribution of iBGP routes into Interior Gateway Protocol (IGP)?Enhanced Interior Gateway Routing Protocol/Open Shortest Path First/Intermediate System-to-Intermediate System (EIGRP/OSPF/IS-IS)?can cause routing loops within the Autonomous System, which is not recommended. By default, iBGP redistribution into IGP is disabled. Issue the bgp redistribute-internal command in order to enable redistribution of iBGP routes into IGP. Precautions must be taken to redistribute specific routes using route-maps into IGP. A sample configuration for redistributing a iBGP learned default route 0.0.0.0/0 into EIGRP is shown in this output. Configurations for OSPF/IS-IS are similar.

router bgp 65345

[...]

bgp redistribute-internal

!

router eigrp 10

[...]

redistribute bgp 65345 route-map check-def

!

ip prefix-list def-route seq 5 permit 0.0.0.0/0

!

route-map check-def permit 10

match ip address prefix-list def-route

HTH

Sundar