需求：
Area 0的路由要求進行彙總，在R3路由器上看到只有一條關於area0路由的彙總。
配置:
R1
interface Loopback0
ip address 10.1.1.1 255.255.255.0
!
interface Loopback1
ip address 10.1.2.1 255.255.255.0
!
interface Loopback2
ip address 10.1.3.1 255.255.255.0
!
interface Loopback4
ip address 1.1.1.1 255.255.255.0
!
interface FastEthernet0/0
no ip address
shutdown
duplex half
!
interface Serial1/0
ip address 12.1.1.1 255.255.255.0
serial restart-delay 0
router ospf 1
router-id 1.1.1.1
log-adjacency-changes
network 1.1.1.1 0.0.0.0 area 0
network 10.1.1.1 0.0.0.0 area 0
network 10.1.2.1 0.0.0.0 area 0
network 10.1.3.1 0.0.0.0 area 0
network 12.1.1.1 0.0.0.0 area 0
!
line con 0
exec-timeout 0 0
password console
logging synchronous
login
R2
interface Loopback0
ip address 2.2.2.2 255.255.255.0
!
interface FastEthernet0/0
no ip address
shutdown
duplex half
!
interface Serial1/0
ip address 12.1.1.2 255.255.255.0
serial restart-delay 0
!
interface Serial1/1
ip address 23.1.1.1 255.255.255.0
serial restart-delay 0
router ospf 1
router-id 2.2.2.2
log-adjacency-changes
area 0 range 10.1.0.0 255.255.252.0
network 2.2.2.2 0.0.0.0 area 0
network 12.1.1.2 0.0.0.0 area 0
network 23.1.1.1 0.0.0.0 area 23
R3
interface Loopback0
ip address 3.3.3.3 255.255.255.0
!
interface FastEthernet0/0
no ip address
shutdown
duplex half
!
interface Serial1/0
ip address 23.1.1.2 255.255.255.0
serial restart-delay 0
router ospf 1
router-id 3.3.3.3
log-adjacency-changes
network 3.3.3.3 0.0.0.0 area 23
network 23.1.1.2 0.0.0.0 area 23
驗證配置：
R3#show ip route
Gateway of last resort is not set
1.0.0.0/32 is subnetted, 1 subnets
O IA 1.1.1.1 [110/129] via 23.1.1.1, 00:01:16, Serial1/0
2.0.0.0/32 is subnetted, 1 subnets
O IA 2.2.2.2 [110/65] via 23.1.1.1, 00:01:16, Serial1/0
3.0.0.0/24 is subnetted, 1 subnets
C 3.3.3.0 is directly connected, Loopback0
23.0.0.0/24 is subnetted, 1 subnets
C 23.1.1.0 is directly connected, Serial1/0
10.0.0.0/32 is subnetted, 3 subnets
O IA 10.1.2.1 [110/129] via 23.1.1.1, 00:01:16, Serial1/0
O IA 10.1.3.1 [110/129] via 23.1.1.1, 00:01:16, Serial1/0
O IA 10.1.1.1 [110/129] via 23.1.1.1, 00:01:16, Serial1/0
12.0.0.0/24 is subnetted, 1 subnets
O IA 12.1.1.0 [110/128] via 23.1.1.1, 00:01:17, Serial1/0
在ABR上進行路由彙總後：area 0 range 10.1.0.0 255.255.252.0
R3#show ip route
Gateway of last resort is not set
1.0.0.0/32 is subnetted, 1 subnets
O IA 1.1.1.1 [110/129] via 23.1.1.1, 02:59:55, Serial1/0
2.0.0.0/32 is subnetted, 1 subnets
O IA 2.2.2.2 [110/65] via 23.1.1.1, 02:59:55, Serial1/0
3.0.0.0/24 is subnetted, 1 subnets
C 3.3.3.0 is directly connected, Loopback0
23.0.0.0/24 is subnetted, 1 subnets
C 23.1.1.0 is directly connected, Serial1/0
10.0.0.0/22 is subnetted, 1 subnets
O IA 10.1.0.0 [110/129] via 23.1.1.1, 02:28:27, Serial1/0
12.0.0.0/24 is subnetted, 1 subnets
O IA 12.1.1.0 [110/128] via 23.1.1.1, 02:59:55, Serial1/0