华为链路状态型路由协议（OSPF）之多区域的配置
路由器的OSPF配置
[R1]display current-configuration configuration ospf
[V200R003C00]
#
ospf 10 router-id 1.1.1.1
area 0.0.0.0
network 1.1.1.1 0.0.0.0
network 172.16.1.1 0.0.0.0
#
return
<R2>system-view
Enter system view, return user view with Ctrl+Z.
[R2]display current-configuration configuration ospf
[V200R003C00]
#
ospf 20 router-id 2.2.2.2
area 0.0.0.0
network 2.2.2.2 0.0.0.0
network 172.16.1.2 0.0.0.0
area 0.0.0.1
network 172.16.2.1 0.0.0.0
#
return
[R3]display current-configuration configuration ospf
[V200R003C00]
#
ospf 30 router-id 3.3.3.3
area 0.0.0.1
network 3.3.3.3 0.0.0.0
network 172.16.2.2 0.0.0.0
area 172.16.10.0
network 172.16.10.1 0.0.0.0
#
return
[R4]display current-configuration configuration ospf
[V200R003C00]
#
ospf 40 router-id 4.4.4.4
area 172.16.10.0
network 4.4.4.4 0.0.0.0
network 172.16.10.2 0.0.0.0
#
return
查看R3的OSPF邻居
[R3]display ospf peer
OSPF Process 30 with Router ID 3.3.3.3
Neighbors
Area 0.0.0.1 interface 172.16.2.2(GigabitEthernet0/0/0)'s neighbors
Router ID: 2.2.2.2 Address: 172.16.2.1
State: Full Mode:Nbr is Slave Priority: 1
DR: 172.16.2.2 BDR: 172.16.2.1 MTU: 0
Dead timer due in 37 sec
Retrans timer interval: 5
Neighbor is up for 00:17:27
Authentication Sequence: [ 0 ]
Neighbors
Area 172.16.10.0 interface 172.16.10.1(GigabitEthernet0/0/1)'s neighbors
Router ID: 4.4.4.4 Address: 172.16.10.2
State: Full Mode:Nbr is Master Priority: 1
DR: 172.16.10.2 BDR: 172.16.10.1 MTU: 0
Dead timer due in 31 sec
Retrans timer interval: 5
Neighbor is up for 00:13:15
Authentication Sequence: [ 0 ]
可以看到有两个邻居，分别通过接口G0/0/1在区域172.16.10.0 ；G0/0/1在区域1中形成了邻居。
R3查看OSPF路由
[R3]display ospf routing
OSPF Process 30 with Router ID 3.3.3.3
Routing Tables
Routing for Network
Destination Cost Type NextHop AdvRouter Area
3.3.3.3/32 0 Stub 3.3.3.3 3.3.3.3 0.0.0.1
172.16.2.0/30 1 Transit 172.16.2.2 3.3.3.3 0.0.0.1
172.16.10.0/30 1 Transit 172.16.10.1 3.3.3.3 172.16.10.0
1.1.1.1/32 2 Inter-area 172.16.2.1 2.2.2.2 0.0.0.1
2.2.2.2/32 1 Inter-area 172.16.2.1 2.2.2.2 0.0.0.1
4.4.4.4/32 1 Stub 172.16.10.2 4.4.4.4 172.16.10.0
172.16.1.0/30 2 Inter-area 172.16.2.1 2.2.2.2 0.0.0.1
Total Nets: 7
Intra Area: 4 Inter Area: 3 ASE: 0 NSSA: 0
[R3]
R3学习到了所有OSPF路由，因为没有配置虚链路，R4没有学习到路由。
R4查看OSPF路由
[R4]display ospf routing
OSPF Process 40 with Router ID 4.4.4.4
Routing Tables
Routing for Network
Destination Cost Type NextHop AdvRouter Area
4.4.4.4/32 0 Stub 4.4.4.4 4.4.4.4 172.16.10.0
172.16.10.0/30 1 Transit 172.16.10.2 4.4.4.4 172.16.10.0
Total Nets: 2
Intra Area: 2 Inter Area: 0 ASE: 0 NSSA: 0
[R4]
这两条路由自己通告的，并没有学习到这个OSPF网络中的其他路由。
R1查看OSPF路由
[R1]display ospf routing
OSPF Process 10 with Router ID 1.1.1.1
Routing Tables
Routing for Network
Destination Cost Type NextHop AdvRouter Area
1.1.1.1/32 0 Stub 1.1.1.1 1.1.1.1 0.0.0.0
172.16.1.0/30 1 Transit 172.16.1.1 1.1.1.1 0.0.0.0
2.2.2.2/32 1 Stub 172.16.1.2 2.2.2.2 0.0.0.0
3.3.3.3/32 2 Inter-area 172.16.1.2 2.2.2.2 0.0.0.0
172.16.2.0/30 2 Inter-area 172.16.1.2 2.2.2.2 0.0.0.0
Total Nets: 5
Intra Area: 3 Inter Area: 2 ASE: 0 NSSA: 0
[R1]
R1除了区域0，还学习到了两条区域之间的路由，但没有学习到区域172.16.10.0的路由，所以需要在R2、R3上补全OSPF虚链路。
配置OSPF虚链路
[R2]ospf 20
[R2-ospf-20]area 1
[R2-ospf-20-area-0.0.0.1]vlink-peer 3.3.3.3
[R2-ospf-20-area-0.0.0.1]quit
[R3]ospf 30
[R3-ospf-30]area 1
[R3-ospf-30-area-0.0.0.1]vlink-peer 2.2.2.2
[R3-ospf-30-area-0.0.0.1]quit
R3上查看虚链路
[R3]display ospf vlink
OSPF Process 30 with Router ID 3.3.3.3
Virtual Links
**Virtual-link Neighbor-id -> 2.2.2.2, Neighbor-State: Full**
Interface: 172.16.2.2 (GigabitEthernet0/0/0)
Cost: 1 State: P-2-P Type: Virtual
Transit Area: 0.0.0.1
Timers: Hello 10 , Dead 40 , Retransmit 5 , Transmit Delay 1
GR State: Normal
[R3]
字体加粗部分看到，R3上已经和2.2.2.2形成了虚链路，建立了完全邻居
R4上查看路由
[R4]display ospf routing
OSPF Process 40 with Router ID 4.4.4.4
Routing Tables
Routing for Network
Destination Cost Type NextHop AdvRouter Area
4.4.4.4/32 0 Stub 4.4.4.4 4.4.4.4 172.16.10.0
172.16.10.0/30 1 Transit 172.16.10.2 4.4.4.4 172.16.10.0
1.1.1.1/32 3 Inter-area 172.16.10.1 3.3.3.3 172.16.10.0
2.2.2.2/32 2 Inter-area 172.16.10.1 3.3.3.3 172.16.10.0
3.3.3.3/32 1 Inter-area 172.16.10.1 3.3.3.3 172.16.10.0
172.16.1.0/30 3 Inter-area 172.16.10.1 3.3.3.3 172.16.10.0
172.16.2.0/30 2 Inter-area 172.16.10.1 3.3.3.3 172.16.10.0
Total Nets: 7
Intra Area: 2 Inter Area: 5 ASE: 0 NSSA: 0
现在R4已经学习到了OSPF网络中的路由。
