配置要求：
用OSPF使PC1与PC2互通
确定R2和R4状态是不是ABR
确保区域456中仅有一个DR，没有BDR
确保区域456DR地址为56.6
确保区域12中没有DR，切发送hello报文的时间为5s

配置步骤：
1、 基本配置：配置PC地址、网关，路由接口地址
2、 PC1与PC2互通
1） 配置思路
区域0为主干区域，非主干区域必须连接主干区域
邻居建立路由router-id不能一致，同网络的区域、子网必须一致
路由器开启OSPF，12.0在区域12,23.0、34.0在区域0、45.0、56.0在区域456
每个路由命名router-id
1.0,2.0网络为直连PC，无需发送OSPF报文，所有用import-route direct添加
AR2\AR4为ABR区域边缘路由器，配置时注意区域切换
2）配置步骤
AR1配置
ospf 1 router-id 1.1.1.1 //进入OSPF进程1，命名routerid
import-route direct//由于192.168.1.0连接PC无需接收OSPF报文，用import-route direct将直连路由加入
area 12 //进入区域12
network 192.168.12.0 0.0.0.255//将192.168.12.0加入OSPF
AR2配置
ospf 1 router-id 2.2.2.2 //进入OSPF进程1，命名routerid
area 12 //进入区域12
network 192.168.12.0 0.0.0.255//将192.168.12.0加入OSPF
area 0 //进入区域0
network 192.168.23.0 0.0.0.255//将192.168.23.0加入OSPF
AR3配置
ospf 1 router-id 3.3.3.3 //进入OSPF进程1，命名routerid
area 0 //进入区域0
network 192.168.23.0 0.0.0.255
network 192.168.34.0 0.0.0.255
AR4配置
ospf 1 router-id 4.4.4.4
area 0
network 192.168.34.0 0.0.0.255
area 456
network 192.168.45.0 0.0.0.255
AR5配置
ospf 1 router-id 5.5.5.5
area 456
network 192.168.45.0 0.0.0.255
network 192.168.56.0 0.0.0.255
AR6配置
ospf 1 router-id 6.6.6.6
import-route direct
area 456
network 192.168.56.0 0.0.0.255

3、 确保区域12中没有DR，切发送hello报文的时间为5s
1） 配置思路
DR、BDR是否存在取决于不同的网络类型
邻居建立Hello报文与dead时间必须相同
12.0网段直连的两个接口网络类型、hello报文长度一致
2）配置步骤
AR1配置：
int g 0/0/0
ospf timer hello 5
ospf network-type p2p
AR2配置
int g 0/0/1
ospf timer hello 5
ospf network-type p2p
4、确保区域456中仅有一个DR，没有BDR，确保区域456DR地址为56.6
1）配置思路
456区域有45.0与56.0两个网段
修改45.0网段直连接口网络类型，确保45.0网络不需要DR\BDR
OSPF权限为0,不参与DR、BDR选举，修改56.5 OSPF权限为0
AR6配置步骤
ospf dr-priority 0

效果：
0、PC1与PC2可通信


1、AR1信息
OSPF Process 1 with Router ID 1.1.1.1
RouterID: 1.1.1.1

Area: 0.0.0.12
Interface: 192.168.12.1 (GigabitEthernet0/0/0) --> 192.168.12.2
Cost: 1 State: P-2-P Type: P2P MTU: 1500
Timers: Hello 5 , Dead 20 , Poll 120 , Retransmit 5 , Transmit Delay 1
192.168.2.0/24 O_ASE 150 1 D 192.168.12.2 GigabitEthernet

2、AR2信息
OSPF Process 1 with Router ID 2.2.2.2
RouterID: 2.2.2.2 Border Router: AREA

Area: 0.0.0.0
Interface: 192.168.23.2 (GigabitEthernet0/0/0)
Cost: 1 State: DR Type: Broadcast MTU: 1500
Priority: 1
Designated Router: 192.168.23.2
Backup Designated Router: 192.168.23.3
Timers: Hello 10 , Dead 40 , Poll 120 , Retransmit 5 , Transmit Delay 1

Area: 0.0.0.12
Interface: 192.168.12.2 (GigabitEthernet0/0/1) --> 192.168.12.1
Cost: 1 State: P-2-P Type: P2P MTU: 1500
Timers: Hello 5 , Dead 20 , Poll 120 , Retransmit 5 , Transmit Delay 1

3、AR3信息
OSPF Process 1 with Router ID 3.3.3.3
RouterID: 3.3.3.3

Area: 0.0.0.0 (MPLS TE not enabled)

Interface: 192.168.23.3 (GigabitEthernet0/0/1)
Cost: 1 State: BDR Type: Broadcast MTU: 1500
Priority: 1
Designated Router: 192.168.23.2
Backup Designated Router: 192.168.23.3
Timers: Hello 10 , Dead 40 , Poll 120 , Retransmit 5 , Transmit Delay 1

Interface: 192.168.34.3 (GigabitEthernet0/0/0)
Cost: 1 State: DR Type: Broadcast MTU: 1500
Priority: 1
Designated Router: 192.168.34.3
Backup Designated Router: 192.168.34.4
Timers: Hello 10 , Dead 40 , Poll 120 , Retransmit 5 , Transmit Delay 1

4、AR4信息
OSPF Process 1 with Router ID 4.4.4.4
RouterID: 4.4.4.4 Border Router: AREA

Area: 0.0.0.0 (MPLS TE not enabled)
Interface: 192.168.34.4 (GigabitEthernet0/0/1)
Cost: 1 State: BDR Type: Broadcast MTU: 1500
Priority: 1
Designated Router: 192.168.34.3
Backup Designated Router: 192.168.34.4
Timers: Hello 10 , Dead 40 , Poll 120 , Retransmit 5 , Transmit Delay 1

Area: 0.0.1.200
Interface: 192.168.45.4 (GigabitEthernet0/0/0) --> 192.168.45.5
Cost: 1 State: P-2-P Type: P2P MTU: 1500
Timers: Hello 10 , Dead 40 , Poll 120 , Retransmit 5 , Transmit Delay 1

5、AR5信息
OSPF Process 1 with Router ID 5.5.5.5
RouterID: 5.5.5.5 Border Router:

Area: 0.0.1.200
Interface: 192.168.45.5 (GigabitEthernet0/0/1) --> 192.168.45.4
Cost: 1 State: P-2-P Type: P2P MTU: 1500
Timers: Hello 10 , Dead 40 , Poll 120 , Retransmit 5 , Transmit Delay 1

Interface: 192.168.56.5 (GigabitEthernet0/0/0)
Cost: 1 State: DROther Type: Broadcast MTU: 1500
Priority: 0
Designated Router: 192.168.56.6
Backup Designated Router: 0.0.0.0
Timers: Hello 10 , Dead 40 , Poll 120 , Retransmit 5 , Transmit Delay 1

6、AR6信息
OSPF Process 1 with Router ID 6.6.6.6
RouterID: 6.6.6.6
Area: 0.0.1.200 (MPLS TE not enabled)

Interface: 192.168.56.6 (GigabitEthernet0/0/1)
Cost: 1 State: DR Type: Broadcast MTU: 1500
Priority: 1
Designated Router: 192.168.56.6
Backup Designated Router: 0.0.0.0
Timers: Hello 10 , Dead 40 , Poll 120 , Retransmit 5 , Transmit Delay 1