Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

Redistribute directly connected links in to OSPF so that connect to all of

All,

I am trying to redistribute directly connected links in to OSPF so that connect to all of my lab network.

I have three routers each has an Ethernet and two serial ports. Router 1 (192.168.1.15/24) is connected to Router 2 (192.168.1.16/24) via their Ethenet ports. Router 1 Serial 0 port (192.168.3.15/24) is connected to a CSU/DSU Router 2 Serial 0 port (192.168.4.15/24) is connected to another CSU/DSU.

When I do a show ip route the following is output:

Router 1

Gateway of last resort is not set

C 192.168.1.0/24 is directly connected, Ethernet0

C 192.168.3.0/24 is directly connected, Serial0

O IA 192.168.4.0/24 [110/74] via 192.168.1.16, 01:07:52, Ethernet0

C 192.168.254.0/24 is directly connected, Loopback0

router1#

Router2

Gateway of last resort is not set

C 192.168.1.0/24 is directly connected, Ethernet0

O IA 192.168.3.0/24 [110/74] via 192.168.1.15, 01:43:42, Ethernet0

C 192.168.4.0/24 is directly connected, Serial0

C 192.168.254.0/24 is directly connected, Loopback0

router2#

When I connect Router 1 Serial 1 port (172.17.10.1/30) to Router 3 Serial port (172.17.10.2/30) via a back to back cables and adding the appropriate clocking commands. I am able to ping from Router 1 to Router 3. This is to be expected since Router 1 and Router 3 are connected and on the same network.

However, I am unable to ping from Router 2 through Router 1 to Router 3. I thought it was due to not redistributing the connected routes (172.17.10.1 and 172.17.10.2) into OSPF protocol. All my attempts to redistribute these connected routes into OSPF have been unsuccessfull. Here is output of the show ip route from all three routers:

Router 1

Gateway of last resort is not set

C 192.168.1.0/24 is directly connected, Ethernet0

C 192.168.3.0/24 is directly connected, Serial0

O IA 192.168.4.0/24 [110/74] via 192.168.1.16, 01:26:51, Ethernet0

C 192.168.254.0/24 is directly connected, Loopback0

172.17.0.0/30 is subnetted, 1 subnets

C 172.17.10.0 is directly connected, Serial1

router1#

Router2

Gateway of last resort is not set

C 192.168.1.0/24 is directly connected, Ethernet0

O IA 192.168.3.0/24 [110/74] via 192.168.1.15, 02:02:28, Ethernet0

C 192.168.4.0/24 is directly connected, Serial0

C 192.168.254.0/24 is directly connected, Loopback0

router2#

Router 3

Gateway of last resort is not set

172.17.0.0/30 is subnetted, 1 subnets

C 172.17.10.0 is directly connected, Serial1

router3#

Any help on this would be appreciated.

1 ACCEPTED SOLUTION

Accepted Solutions
New Member

Re: Redistribute directly connected links in to OSPF so that con

I guess I should follow this up with a suggestion. Even if you manage to get the 172.17.10.0 /30 subnet propagated to R2, R3 will still have no reachability to any other subnet based on the R3 route table you posted. You will have to either configure a static default on R3 or run OSPF over the Serial Link between R1 and R3. I'm at a small disadvantage since I haven't seen your OSPF configuration (areas, etc..). I could be wrong as a result. Good luck

5 REPLIES
New Member

Re: Redistribute directly connected links in to OSPF so that con

Just curious: Are you adding the "subnets" keyword at the end of your "redistribute connected" syntax on R1 ?

New Member

Re: Redistribute directly connected links in to OSPF so that con

I guess I should follow this up with a suggestion. Even if you manage to get the 172.17.10.0 /30 subnet propagated to R2, R3 will still have no reachability to any other subnet based on the R3 route table you posted. You will have to either configure a static default on R3 or run OSPF over the Serial Link between R1 and R3. I'm at a small disadvantage since I haven't seen your OSPF configuration (areas, etc..). I could be wrong as a result. Good luck

New Member

Re: Redistribute directly connected links in to OSPF so that con

add output of

#sh run

#sh ip ospf nei

#sh ip route

from your R1, R2, R3.

New Member

Re: Redistribute directly connected links in to OSPF so that con

its so simple router2 not have entry for 172.17.0.0 so how it is posible to ping that network if you configer static route on router 2 like

R2(config)#ip route 172.17.x.x 255.255.x.x s0

and on Router 3

R3(config)#ip route 192.168.x.x 255.255.x.x s1

now you can ping from R2 to R3 and R3 to R2

Silver

Re: Redistribute directly connected links in to OSPF so that con

While the static routes suggested will work, I think you wish to use OSPF in your network, and apparently Router 3 is not participating in the OSPF process. As you can see it does not know any OSPF routes. It can ping router 1 because it knows it has directly connected, but cannot ping router 2, because it is not aware of the 192.168.0.0 network. Likewise, Router 2 is not aware of the 172.17.0.0 network. Note also that deafult routes is not set on the network.

While you are trying to redstribute connected interfaces into the OSPF process, it will be better to make the interfaces in the 172.17.0.0 network part of the OSPF process. Add a line such as

Router OSPF 10

network 172.17.0.0 area 0

on router 1 and router 3.

If you redistribute connected interfaces on Router 1 and 2, with starting the OSPF process on router 3, and adding the 172.17.0.0 interfaces, it will not work. The beauty is that once OSPF process is started, with the interfaces added, you will not need to redistribute connected interfaces anymore

NB: Use the right OSPF areas and process ID as appropriately used in your network.

191
Views
3
Helpful
5
Replies
CreatePlease login to create content