Lab  7.4.6 OSPF Default Information 

Objectives:

  • To inject a static default route into the entire OSPF routing domain.

Note: 

This is one of the most powerful commands in OSPF routing. It informs all the routers in OSPF of an exterior default route.

Complete the following steps:

  1. Setup the lab as shown in the diagram. 
  2. Assign IP addresses to each interface. 
  3. Enable OSPF as the routing protocol. 
  4. Check to see if neighbor relationships exist between all routers

    Verify your configurations are as follows:

    RTA's configuration is:

    hostname router-a
    Loopback0
    ip address 1.1.16.172 255.255.255.0
    interface FastEthernet0/0
    ip address 172.16.1.1 255.255.255.0
    interface Serial0/0
    ip address 192.168.0.1 255.255.255.0
    clockrate 56000
    router ospf 1
    network 206.202.16.0 0.0.0.255 area 0
    network 192.168.0.0 0.0.0.255 area 0

    RTB's configuration is:

    hostname router-b
    interface Loopback0
    ip address 2.0.168.192 255.255.255.0
    interface Serial0/0
    ip address 192.168.1.1 255.255.255.0
    interface serial 0/1 
    ip address 192.168.0.2 255.255.255.0
    clockrate 56000
    router ospf 1
    network 192.168.0.0 0.0.0.255 area 0
    network 192.168.1.0 0.0.0.255 area 1

    RTC's configuration is:

    hostname router-c
    interface Loopback0
    ip address 2.1.168.192 255.255.255.0
    interface Serial0/1
    ip address 192.168.1.2 255.255.255.0
    router ospf 1
    network 192.168.1.0 0.0.0.255 area 1

  5. Go to each router and issue the command show ip route. Is there a gateway of last resort?

    On Router C:
    Ping 172.16.1.1 and record your results below:

  6. On Router A:

    Issue the following commands:

    router-a(config)#ip route 0.0.0.0 0.0.0.0 fe0/0
    router-a(config)#router ospf 1
    router-a(config-router)#default-information originate
    router-a(config-router)#control Z

  7. Go to each router and issue the command show ip route.
    Is there a gateway of last resort?

    On Router C:

    Ping 172.16.1.1 and record your results below:
    Trace 195.6.0.1 and record your result below:


Note:

The exterior provider will setup and advertise a route back to your OPSF network. This will allow packets back into your network