OSPF虚链路
1、 OSPF虚链路
a、当非主干区域与主干区域AREA0不连续时必须建立虚链路
b、虚链路配置：area area-id virtual-link router-id
area-id：指虚链路经过的中转区的区域id
router-id：指定虚链路另一端的路由器id
R1配置
en
conf t
hostname R1
int loopback 0
ip address 1.1.1.1 255.255.255.0
no shutdown
exit
int f0/0
ip address 192.168.1.1 255.255.255.0
no shutdown
exit
router ospf 1
network 1.1.1.0 0.0.0.255 area 0
network 192.168.1.0 0.0.0.255 area 0
exit
end
R2配置
en
conf t
hostname R2
int loopback 0
ip address 2.2.2.2 255.255.255.0
no shutdown
exit
int f0/0
ip address 192.168.1.2 255.255.255.0
no shutdown
exit
int f0/1
ip address 192.168.2.1 255.255.255.0
no shutdown
exit
router ospf 1
network 2.2.2.0 0.0.0.255 area 0
network 192.168.1.0 0.0.0.255 area 0
network 192.168.2.0 0.0.0.255 area 0
exit
end
R3配置
en
conf t
hostname R3
int loopback 0
ip address 3.3.3.3 255.255.255.0
no shutdown
exit
int f0/1
ip address 192.168.2.2 255.255.255.0
no shutdown
exit
int f0/0
ip address 192.168.3.1 255.255.255.0
no shutdown
exit
router ospf 1
network 3.3.3.0 0.0.0.255 area 0
network 192.168.2.0 0.0.0.255 area 0
network 192.168.3.0 0.0.0.255 area 1
area 1 virtual-link 5.5.5.5
exit
end
R4配置
en
conf t
hostname R4
int loopback 0
ip address 4.4.4.4 255.255.255.0
no shutdown
exit
int f0/0
ip address 192.168.3.2 255.255.255.0
no shutdown
exit
int f0/1
ip address 192.168.4.1 255.255.255.0
no shutdown
exit
router ospf 1
network 4.4.4.0 0.0.0.255 area 1
network 192.168.3.0 0.0.0.255 area 1
network 192.168.4.0 0.0.0.255 area 1
exit
end
R5配置
en
conf t
hostname R5
int loopback 0
ip address 5.5.5.5 255.255.255.0
no shutdown
exit
int f0/1
ip address 192.168.4.2 255.255.255.0
no shutdown
exit
int f0/0
ip address 192.168.5.1 255.255.255.0
no shutdown
exit
router ospf 1
network 5.5.5.0 0.0.0.255 area 1
network 192.168.4.0 0.0.0.255 area 1
network 192.168.5.0 0.0.0.255 area 2
area 1 virtual-link 3.3.3.3
exit
end
R6配置
en
conf t
hostname R6
int loopback 0
ip address 6.6.6.6 255.255.255.0
no shutdown
exit
int f0/0
ip address 192.168.5.2 255.255.255.0
no shutdown
exit
router ospf 1
network 6.6.6.0 0.0.0.255 area 2
network 192.168.5.0 0.0.0.255 area 2
exit
end
R6#show ip ospf database
OSPF Router with ID (6.6.6.6) (Process ID 1)
Router Link States (Area 2)
Link ID ADV Router Age Seq# Checksum Link count
6.6.6.6 6.6.6.6 41 0x80000003 0x0050c8 2
5.5.5.5 5.5.5.5 41 0x80000002 0x00ba90 1
Net Link States (Area 2)
Link ID ADV Router Age Seq# Checksum
192.168.5.2 6.6.6.6 41 0x80000001 0x00a0be
Summary Net Link States (Area2)
Link ID ADV Router Age Seq# Checksum
192.168.2.0 5.5.5.5 21 0x80000001 0x004993
192.168.1.0 5.5.5.5 21 0x80000002 0x005c7f
3.3.3.3 5.5.5.5 21 0x80000003 0x0082b7
2.2.2.2 5.5.5.5 21 0x80000004 0x00b883
1.1.1.1 5.5.5.5 21 0x80000005 0x00ee4f
R6#show ip route
Codes: C - connected, S - static, I - IGRP,R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRPexternal, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPFNSSA external type 2
E1 - OSPF external type 1, E2 - OSPFexternal type 2, E - EGP
i - IS-IS, L1 - IS-ISlevel-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
1.0.0.0/32is subnetted, 1 subnets
O IA 1.1.1.1 [110/6] via 192.168.5.1, 00:00:22, FastEthernet0/0
2.0.0.0/32is subnetted, 1 subnets
O IA 2.2.2.2 [110/5] via 192.168.5.1, 00:00:22, FastEthernet0/0
3.0.0.0/32 is subnetted, 1 subnets
O IA 3.3.3.3 [110/4] via 192.168.5.1, 00:00:22, FastEthernet0/0
6.0.0.0/24 issubnetted, 1 subnets
C 6.6.6.0 is directly connected, Loopback0
O IA 192.168.1.0/24[110/5] via 192.168.5.1, 00:00:22, FastEthernet0/0
O IA 192.168.2.0/24[110/4] via 192.168.5.1, 00:00:22, FastEthernet0/0
C 192.168.5.0/24is directly connected, FastEthernet0/0
解释：R6能收到域间路由信息，说明虚链路创建成功。