OSPF Totally Stub Area Configuration on Gns3 P-3:

Part-3: OSPF Totally Stub Area Configuration

Prerequisite for this Lab: Part-1

What is totally stub Area?

A totally stub area is similar to a stub area. However, this area does not allow summary routes in addition to not having external routes, that is, inter-area (IA) routes are not summarized into totally stubby areas. The only way for traffic to get routed outside of the area is a default route which is the only Type-3 LSA advertised into the area. (Ref: Wikipedia.com)

 

(For OSPF and IP configuration visit part-1)

Objective:

In Our topology we find the area-2 as totally stubby area, it will block typ-3, 4 and 5 LSA and show only the connected subnets.

Before the configuration you can see that it is displaying all routes:

R5 totally Stubby area configuration commands:

R5(config)#router ospf 1

R5(config-router)#area 2 stub

R4 totally Stubby area configuration commands:

R4(config-router)#   area 2 stub no-summary

Verification:

Show ip route on R5, you would find only connected and a default route for external network:

 

 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