Posts tagged ODR

In this article we’ll do a short ODR (On Demand Routing) lab. ODR is a simple routing protocol targeted at hub and spoke topologies, it uses CDP to propagate routing updates. This is one of the technologies that might be on the CCIE exams. I will be including my Dynagen/GNS3 .net file at the end of this post. Here is our topology:

Let’s go through the config:

R1

hostname R1
!
interface Loopback0
 ip address 1.1.1.1 255.255.255.255
!
interface Serial0/0
 ip address 10.1.0.1 255.255.255.252
!
interface Serial0/1
 ip address 10.1.1.1 255.255.255.252
!
interface Serial0/2
 ip address 10.1.2.1 255.255.255.252
!
router odr

We configure the hostname and our Loppback and Serial interfaces. The important command here is “router odr”, this turns ODR on. This command is ONLY run on the hub.

R2:

hostname R2
!
interface Loopback0
 ip address 2.2.2.2 255.255.255.255
!
interface Serial0/0
 ip address 10.1.0.2 255.255.255.252

R3:

hostname R3
!
interface Loopback0
 ip address 3.3.3.3 255.255.255.255
!
interface Serial0/0
 ip address 10.1.1.2 255.255.255.252

R4:

hostname R4
interface Loopback0
 ip address 4.4.4.4 255.255.255.255
!
interface Serial0/0
 ip address 10.1.2.2 255.255.255.252

We now have our hostnames and interfaces configured on R1, R2 and R3. Notice we DO NOT use the “router odr” command on the spokes.

Surprisingly, that is all there is to it! Let’s verify our config: