​​Summary:

1. Add a loopback interface to Belt with the IP address 184.51.1.2/24 and a default route to 184.51.1.1. This will simulate an Internet connection.

2. Have Belt advertise the default route to the other routers via OSPF. The route should exist even if Belt does not have a default route.

 

 

 

1. Add a loopback interface to Belt with the IP address 184.51.1.2/24 and a default route to 184.51.1.1. This will simulate an Internet connection.

Belt: note after adding a default route to the internet, Belt becomes ASBR

int loopback 5
 ip address 184.51.1.2 255.255.255.0
ip route 0.0.0.0 0.0.0.0 184.51.1.1

default-information originate



#Test:

before the change:

Shoe#show ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

     10.0.0.0/8 is variably subnetted, 10 subnets, 2 masks
O IA    10.2.0.0/16 [110/138] via 10.51.1.1, 05:25:10, Serial1/0
C       10.1.3.0/24 is directly connected, FastEthernet0/0
O IA    10.0.0.0/24 [110/74] via 10.51.1.1, 18:41:46, Serial1/0
O IA    10.1.0.0/16 [110/138] via 10.51.1.1, 05:29:40, Serial1/0
C       10.51.1.0/24 is directly connected, Serial1/0
C       10.51.0.0/24 is directly connected, Loopback0
C       10.51.3.0/24 is directly connected, Loopback2
C       10.51.2.0/24 is directly connected, Loopback1
C       10.51.5.0/24 is directly connected, Loopback4
C       10.51.4.0/24 is directly connected, Loopback3



after the change:


Shoe#show ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route

Gateway of last resort is 10.51.1.1 to network 0.0.0.0

     10.0.0.0/8 is variably subnetted, 10 subnets, 2 masks
O IA    10.2.0.0/16 [110/138] via 10.51.1.1, 05:26:07, Serial1/0
C       10.1.3.0/24 is directly connected, FastEthernet0/0
O IA    10.0.0.0/24 [110/74] via 10.51.1.1, 18:42:43, Serial1/0
O IA    10.1.0.0/16 [110/138] via 10.51.1.1, 05:30:37, Serial1/0
C       10.51.1.0/24 is directly connected, Serial1/0
C       10.51.0.0/24 is directly connected, Loopback0
C       10.51.3.0/24 is directly connected, Loopback2
C       10.51.2.0/24 is directly connected, Loopback1
C       10.51.5.0/24 is directly connected, Loopback4
C       10.51.4.0/24 is directly connected, Loopback3
O*E2 0.0.0.0/0 [110/1] via 10.51.1.1, 00:00:10, Serial1/0 !----------------------------------------------------------- default route
Shoe#
 

2. Have Belt advertise the default route to the other routers via OSPF. The route should exist even if Belt does not have a default route.

Belt:


int lo5 !-------------------shutdown the loopback interface, then use "always" command to advertise default route even there is no default route
 shutdown

router ospf 1
 no default-information originate
 default-information originate always

 

 

 

 

 

 

 

 

 

 

 

 

 

-Yu