Why this subnets can not be redistributed?

[teru-lei]

Hi All,

I met the following case:

...................... R2--eth0

......................./

eth0----R1--

..................... \

........................R3--eth0

In R1, s0 is connected to R2, s1 is connected to r3. R1 and R2 is running ospf,

R1 and R3 is running eigrp. R1 have a loopback lo0. in ospf, I use the following command to redistribute lo0 and eigrp to ospf in "router ospf":

redistribute connected subnets route-map redislo0 (the route-map just allow lo0 to be redistributed)

redistribute eigrp 1 subnets

when I use the "show ip route" in R2, I can not see the subnet between R1 and R3. and if I remove the route-map in the "redistribute connected" command, I can see the subnet between R1 and R3 in R2. So that it's the route-map problem. But the subnet between R1 and R3 is running eigrp 1, why the subnet can not be redistributed? That's the same when I redistribute ospf to eigrp using "redistribute connected route-map redislo0". Does anybody know the reason? Thank You!

Best Regards

Teru Lei

[chrihussey]

If I understand your question correctly, the networks associated with the local serial interfaces on R1 are not being redistributed by the redistribute eigrp or ospf command. This is because these should be considered "connected" subnets regardless of the fact that their networks are configured in OSPF or EIGRP. If you do a "sh ip route" on R1 you will see these networks come up as connected and not as EIGRP or OSPF routes.

For that reason, when doing any form of redistibution between protocols on a router, any networks on directly connected interfaces need to be regarded as such and not as part of their configured protocol.

[thisisshanky]

Hi Teru,

The subnet between R1 and R3 is running EIGRP. But that subnet appears to R1 as directly connected route, and hence on R1 it will see the subnet with "C".

To redistribute this route, into OSPF you will need to permit this network address in the access-list that you are using to redistribute the loopback network.

Hope thats clear!

[teru-lei]

Hi,

Thank you for your reply. But to my knowledge, the redistribute command not just "see" the routing, also the database. So the subnet between R1 and R3 should be redistributed although the routing table is "C". The connected network should be redistributed expect the subnet is running ISIS. I also tried to remove the command "redistribute connected" and the subnet appear in R2 again.

Best Regards

Teru Lei