默认路由

默认路由—匹配的是所有网段

当路由器在路由表中找不到目标网络的路由条目时，路由器把请求转发到默认路由接口

在末梢网络（该路由器后面没有在接其他路由器）时可以使用默认路由

默认路由是静态路由的一种特殊形式，它属于静态路由中的一种，使用它是有条件的，只能在末梢网络中使用

 

 

例题：

R1：

<Huawei>undo terminal monitor

Info: Current terminal monitor is off.

<Huawei>system-view

Enter system view, return user view with Ctrl+Z.

[Huawei]sysname R1

[R1]user-interface console 0

[R1-ui-console0]idle-timeout 0 0

[R1-ui-console0]quit

[R1]int g0/0/0

[R1-GigabitEthernet0/0/0]ip add 10.1.1.1 24

[R1-GigabitEthernet0/0/0]undo shut

Info: Interface GigabitEthernet0/0/0 is not shutdown.

[R1-GigabitEthernet0/0/0]int loop 0

[R1-LoopBack0]ip add 1.1.1.1 32

[R1-LoopBack0]quit

[R1]ip route-static 0.0.0.0 0.0.0.0 10.1.1.2

前4个0代表所有网段，后4个0代表子网掩码，10.1.1.2代表下一跳的接口

 

 

R2：

 

<Huawei>undo terminal monitor

 

Info: Current terminal monitor is off.

 

<Huawei>system-view

 

Enter system view, return user view with Ctrl+Z.

 

[Huawei]sysname R2

 

[R2]user-interface console 0

 

[R2-ui-console0]idle-timeout 0 0

 

[R2-ui-console0]quit

 

[R2]int g0/0/0

 

[R2-GigabitEthernet0/0/0]ip add 10.1.1.2 24

 

[R2-GigabitEthernet0/0/0]undo shut

 

Info: Interface GigabitEthernet0/0/0 is not shutdown.

 

[R2-GigabitEthernet0/0/0]int g0/0/1

 

[R2-GigabitEthernet0/0/1]ip add 10.1.2.2 24

 

[R2-GigabitEthernet0/0/1]undo shut

 

Info: Interface GigabitEthernet0/0/1 is not shutdown.

 

[R2-GigabitEthernet0/0/1]int loop 0

 

[R2-LoopBack0]ip add 2.2.2.2 32

 

[R2-LoopBack0]quit

 

R3：

<Huawei>undo terminal monitor

Info: Current terminal monitor is off.

<Huawei>system-view

Enter system view, return user view with Ctrl+Z.

[Huawei]sysname R3

[R3]user-interface console 0

[R3-ui-console0]idle-timeout 0 0

[R3-ui-console0]quit

[R3]int g0/0/0

[R3-GigabitEthernet0/0/0]ip add 10.1.2.3 24

[R3-GigabitEthernet0/0/0]undo shut

Info: Interface GigabitEthernet0/0/0 is not shutdown.

[R3-GigabitEthernet0/0/0]int loop 0

[R3-LoopBack0]ip add 3.3.3.3 32

[R3-LoopBack0]quit

[R3]ip route-static 0.0.0.0 0.0.0.0 10.1.2.2