I cannot get my router and switch to work communicate with ospf

[memelord]

Hello, I cannot get my switch and router to communicate. I am using OSPF and I can get Router 1 to communicate with Router 2 but I cannot get the Switch to communicate.

[paul driver]

Hello
Your switch has no ip connectivity to the rtrs?

[BruteForce · Accepted solution]

R2 looks like it has

 /30 interface Gig0/1

that's ready to have a connection to S1, but S1's physical ports are configured as layer 2 trunks. Loopback1 on SW1 has an ip, but that's a "virtual interface". I don't typically see them configured as

 /30s

and definitely not as

 ospf point-to-point

but maybe someone can elaborate on a use case for that.

SW1 needs a layer 3 connection to R2, maybe in the

10.0.3.0/30 network

Mirror the

Gig0/1 R2 configs (with 10.0.3.2)

on whatever port SW1 will use to connect to R2.

[MHM Cisco World]

you are not run 

ip routing

in SW ?? may be this issue here 

[Richard Burts]

I agree with @MHM Cisco World that we do not see ip routing enabled on the switch, although there are multiple commands in the config that would only be valid if ip routing were enabled. So that might be part of the issue. I agree with @BruteForce that the loopback interface on the switch is odd and not functional. It has an IP and ospf statements like it expected to run ospf. But the loopback does not have any physical connectivity and so running ospf on it does not make sense.

The basic problem here is that both routers have G0/0 with interfaces in a /30 subnet. They obviously are connected to switch ports in vlan 1 and can communicate with each other. But the switch does not have an IP address in vlan 1 (and there is not room in the subnet for a third device). So the switch is not able to communicate IP with either router.