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昨天，和朋友在機(jī)房討論組網(wǎng)問題，當(dāng)討論到路由器間通信時，朋友問起為什么非要配置路由選擇協(xié)議。以前一般是根據(jù)配置手冊或者經(jīng)驗(yàn)配置也沒有仔細(xì)考慮過這個問題。想了想，應(yīng)該是這樣理解的(如下)。

如果多個網(wǎng)段之間要實(shí)現(xiàn)通信，必須使用路由器，這個毫無疑問。如果多個網(wǎng)段之間存在多個可選擇的路徑，最方便的是采取配置路由選擇協(xié)議的方法，簡單點(diǎn)的網(wǎng)絡(luò)可以采用RIP協(xié)議，如果是復(fù)雜的網(wǎng)絡(luò)則可以采用OSPF。當(dāng)然在選擇的路徑不多時也可以采用靜態(tài)路由的方法。

但是，當(dāng)多個網(wǎng)段之間只有一條路徑時，那么僅僅是配置靜態(tài)路由就足夠了。如果是在企業(yè)中工作，那么往往配置簡單的靜態(tài)路由就足夠了。

為了更有說服力和便于理解我用CPT(Cisco Packet Tracer)演示了一下。

拓?fù)鋱D如下圖所示：

分別有四個網(wǎng)段，10.0.0.0/8、112.237.228.0/24、192.168.10.0/24、211.86.104.0/24。

靜態(tài)路由設(shè)置如下：

ip route 192.168.10.0 255.255.255.0 112.237.228.1

ip route 211.86.104.0 255.255.255.0 112.237.228.1

ip route 10.0.0.0 255.0.0.0 112.237.228.244

ip route 211.86.104.0 255.255.255.0 192.168.10.1

ip route 112.237.228.0 255.255.255.0 192.168.10.2

ip route 10.0.0.0 255.0.0.0 192.168.10.2

配置如下：

1.PC0的IP配置：

Packet Tracer PC Command Line 1.0

PC>ipconfig

IP Address......................: 10.0.0.3

Subnet Mask.....................: 255.0.0.0

Default Gateway.................: 10.0.0.1

PC>

2.PC1的IP配置：

Packet Tracer PC Command Line 1.0

PC>ipconfig

IP Address......................: 211.86.104.52

Subnet Mask.....................: 255.255.255.0

Default Gateway.................: 211.86.104.254

PC>

3.R1的配置：

Router>enable

Router#configure terminal

Enter configuration commands, one per line. End with CNTL/Z.

Router(config)#hostname R1

R1(config)#interface FastEthernet0/1

R1(config-if)#ip address 10.0.0.1 255.0.0.0

R1(config-if)#no shutdown

%LINK-5-CHANGED: Interface FastEthernet0/1, changed state to up

R1(config-if)#end

R1#

%SYS-5-CONFIG_I: Configured from console by console

R1#conf t

Enter configuration commands, one per line. End with CNTL/Z.

R1(config)#int f0/0

R1(config-if)#ip addr 112.237.228.244 255.255.255.0

R1(config-if)#no shutdown

%LINK-5-CHANGED: Interface FastEthernet0/0, changed state to up

R1(config-if)#end

R1#

%SYS-5-CONFIG_I: Configured from console by console

R1#conf t

Enter configuration commands, one per line. End with CNTL/Z.

R1(config)#ip route 192.168.10.0 255.255.255.0 112.237.228.1

R1(config)#ip route 211.86.104.0 255.255.255.0 112.237.228.1

R1(config)#end

R1#

%SYS-5-CONFIG_I: Configured from console by console

R1#

4.R2的配置：

Router>enable

Router#configure terminal

Enter configuration commands, one per line. End with CNTL/Z.

Router(config)#hostname R2

R2(config)#

R2(config)#interface FastEthernet0/1

R2(config-if)#ip address 112.237.228.1 255.255.255.0

R2(config-if)#no shutdown

%LINK-5-CHANGED: Interface FastEthernet0/1, changed state to up

R2(config-if)#

R2(config-if)#exit

R2(config)#interface FastEthernet0/0

R2(config-if)#ip address 192.168.10.2 255.255.255.0

R2(config-if)#no shutdown

%LINK-5-CHANGED: Interface FastEthernet0/0, changed state to up

R2(config-if)#end

R2#conf t

Enter configuration commands, one per line. End with CNTL/Z.

R2(config)#ip route 10.0.0.0 255.0.0.0 112.237.228.244

R2(config)#ip route 211.86.104.0 255.255.255.0 192.168.10.1

R2(config)#end

R2#

%SYS-5-CONFIG_I: Configured from console by console

R2#

5.R3的配置：

Router>enable

Router#configure terminal

Enter configuration commands, one per line. End with CNTL/Z.

Router(config)#hostname R3

R3(config)#

R3(config)#interface FastEthernet0/1

R3(config-if)#ip address 192.168.10.1 255.255.255.0

R3(config-if)#no shutdown

%LINK-5-CHANGED: Interface FastEthernet0/1, changed state to up

R3(config-if)#

R3(config-if)#exit

R3(config)#interface FastEthernet0/0

R3(config-if)#ip address 211.86.104.254 255.255.255.0

R3(config-if)#no shutdown

R3(config-if)#

%LINK-5-CHANGED: Interface FastEthernet0/0, changed state to up

R3>enable

R3#conf t

Enter configuration commands, one per line. End with CNTL/Z.

R3(config)#ip route 112.237.228.0 255.255.255.0 192.168.10.2

R3(config)#ip route 10.0.0.0 255.0.0.0 192.168.10.2

R3(config)#end

R3#

%SYS-5-CONFIG_I: Configured from console by console

R3#

6.使用tracert進(jìn)行測試：

測試從PC0能否路由到PC1。

結(jié)果表明測試成功。

測試從PC1能否路由到PC0。

結(jié)果表明測試成功。