前言
1.为什么OSPF要划分多区域？
①减少LSDB库的规模；②减少LSA条目的数量；③SPF影响的设备数量减少
2.OSPF的LAS信息分为：
①区域内；②区域间；③区域外
一、第一部分
1.区域内路由计算
2.区域间路由计算
3.外部路由计算
二、实验操作
实验一：单区域OSPF
前期配置
拓扑图
AR2
AR5
命令配置
AR1
The device is running!
<Huawei>system-view
Enter system view, return user view with Ctrl+Z.
[Huawei]sysname AR1
[AR1]undo info enable
Info: Information center is disabled.
[AR1]int GigabitEthernet 0/0/0
[AR1-GigabitEthernet0/0/0]ip address 10.1.124.1 24
[AR1-GigabitEthernet0/0/0]q
-----------------初始接口IP配置----------------------------------------------------
[AR1]ospf 1 router-id 10.1.1.1 \\配置ospfID
[AR1-ospf-1]area 0 创建区域零
[AR1-ospf-1-area-0.0.0.0]network 10.1.124.1 0.0.0.0 宣告将接口IP加入到area 0中
[AR1-ospf-1-area-0.0.0.0]AR2
The device is running!
<Huawei>sys
Enter system view, return user view with Ctrl+Z.
[Huawei]sysname AR2
[AR2]undo info enable
Info: Information center is disabled.
[AR2]int gi 0/0/0
[AR2-GigabitEthernet0/0/0]ip address 10.1.124.2 24
[AR2-GigabitEthernet0/0/0]int gi0/0/2
[AR2-GigabitEthernet0/0/2]ip address 10.1.23.2 24
[AR2-GigabitEthernet0/0/2]q
[AR2]int Serial 1/0/0
[AR2-Serial1/0/0]ip address 10.1.25.2 24
[AR2-Serial1/0/0]q
[AR2]
-----------------初始接口IP配置----------------------------------------------------
[AR2]ospf 1 router-id 10.2.2.2
[AR2-ospf-1]area 0
[AR2-ospf-1-area-0.0.0.0]network 10.1.124.2 0.0.0.0
[AR2-ospf-1-area-0.0.0.0]network 10.1.23.2 0.0.0.0
[AR2-ospf-1-area-0.0.0.0]network 10.1.25.2 0.0.0.0
[AR2-ospf-1-area-0.0.0.0]AR3
The device is running!
<Huawei>sys
Enter system view, return user view with Ctrl+Z.
[Huawei]sysname AR3
[AR3]undo info enable
Info: Information center is disabled.
[AR3]int g0/0/0
[AR3-GigabitEthernet0/0/0]ip address 10.1.23.3 24
[AR3-GigabitEthernet0/0/0]q
[AR3]
-----------------初始接口IP配置----------------------------------------------------
[AR3]ospf 1 rou 10.3.3.3
[AR3-ospf-1]a 0
[AR3-ospf-1-area-0.0.0.0]network 10.1.23.3 0.0.0.0
[AR3-ospf-1-area-0.0.0.0]AR4
The device is running!
<Huawei>sys
Enter system view, return user view with Ctrl+Z.
[Huawei]sysname AR4
[AR4]undo info enable
Info: Information center is disabled.
[AR4]int g0/0/0
[AR4-GigabitEthernet0/0/0]ip address 10.1.124.4 24
[AR4-GigabitEthernet0/0/0]q
[AR4]
-----------------初始接口IP配置----------------------------------------------------
[AR4]ospf 1 rou 10.4.4.4
[AR4-ospf-1]area 0
[AR4-ospf-1-area-0.0.0.0]q
[AR4-ospf-1]q
[AR4]int g0/0/0
[AR4-GigabitEthernet0/0/0]ospf enable 1 area 0
[AR4-GigabitEthernet0/0/0]
\*把接口ip宣告进ospf有两种方式
第一种：在ospf 1 area 0中把IP地址加进去，既[AR3-ospf-1-area-0.0.0.0]network 10.1.23.3 0.0.0.0
第二种：在对应的接种中宣告此接口属于ospf的哪个进程哪个区域，既[AR4-GigabitEthernet0/0/0]ospf enable 1 area 0 此接口属于ospf进程1的区域0中。这两种方式效果一样。
但第二种方式在宣告前要把ospf进程和区域事先创建好
*\AR5
The device is running!
<Huawei>
<Huawei>sys
Enter system view, return user view with Ctrl+Z.
[Huawei]sysname AR5
[AR5]undo in en
Info: Information center is disabled.
[AR5]int Serial 1/0/0
[AR5-Serial1/0/0]ip address 10.1.25.5 24
[AR5-Serial1/0/0]q
[AR5]
-----------------初始接口IP配置----------------------------------------------------
[AR5]ospf 1 rou 10.5.5.5 \\创建进程为1的ospf，router-id为10.5.5.5
[AR5-ospf-1]area 0 \\在ospf 1中创建区域0
[AR5-ospf-1-area-0.0.0.0]q
[AR5-ospf-1]q
[AR5]int s 1/0/0 \\进去串口serial 1/0/0
[AR5-Serial1/0/0]ospf enable 1 area 0 \\宣告此接口属于ospf 1 area 0
[AR5-Serial1/0/0]dis this \\查看一下接口状态
[V200R003C00]
#
interface Serial1/0/0
link-protocol ppp
ip address 10.1.25.5 255.255.255.0
ospf enable 1 area 0.0.0.0
#
return
[AR5-Serial1/0/0]