top of page

​​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

​

bottom of page