OSPF Stub Area Configuration on GNS3 P-2

Part-2: OSPF Stub Area Configuration

This is part-2 of OSPF Stub Area Configuration. In Part-1 I have configured OSPF on all the routers. In this part I will show you how to configure Stub area.

What is Stub Area?

A stub area is an area which does not receive route advertisements external to the autonomous system (AS) and routing from within the area is based entirely on a default route. (Ref: wikipedia.com)

Objective:

In our topology R3 is advertising the RIP routes to internal OSPF, these are type-5 LSA, Stub area block these LSA type. In this topology I define the area-1 as stub area so that R1 and area-1 don’t receive these routes but can get these via ABR (R2).

Before stub area configuration you can see that R1 is slowing all RIP routes in its routing table.

Show ip route

R1 Stub area configuration commands:

 R1(config)#router ospf 1

 R1(config)#area 1 stub

R2 Stub area configuration commands:

R1(config)#router ospf 1

R1(config-router)#area 1 stub

For summarization:

R1(config-router)#area 1 range 10.1.0.0 255.255.248.0

Verification:

Show ip route on R1, you would not find any RIP route but a default route for external RIP routes:

 

 This lab consists of following four parts.

 Part-1: IP(s) and OSPF Multi Area Configuration

 Part-2: OSPF Stub Area Configuration

 Part-3: OSPF Totally Stub Area Configuration

 Part-4: OSPF Not So Stubby Area Configuration