NA-NP-IE系列實驗9:預設路由

實驗9:預設路由

所謂的預設路由，是指路由器在路由表中如果找不到到達目的網絡的具體路由時，最後

會采用的路由。預設路由通常會在存根網絡（Stub network，即隻有一個出口的網絡）中使

用。如圖，圖中左邊的網絡到Internet 上隻有一個出口，是以可以在R2 上配置預設路

由。指令為：ip route 0.0.0.0 0.0.0.0 { 網關位址 | 接口 }

例子：ip route 0.0.0.0 0.0.0.0 s0/0

例子：ip route 0.0.0.0 0.0.0.0 12.12.12.2

1. 實驗目的

通過本實驗，讀者可以掌握如下技能：

（1） 預設路由的使用場合

（2） 預設路由的配置

2. 實驗拓撲

如圖。

3. 實驗步驟

Router>en

Router#conf t

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

Router(config)#ho r0

r0(config)#no ip domain-loo

r0(config)#lin c 0

r0(config-line)#logg s

r0(config-line)#exec-t 00

r0(config-line)#exit

r0(config)#end

r0#

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

r0#conf t

r0(config)#int loo 1

%LINK-5-CHANGED: Interface Loopback1, changed state to up

%LINEPROTO-5-UPDOWN: Line protocol on Interface Loopback1, changed state to up

r0(config-if)#

r0(config-if)#ip add 3.3.3.3 255.255.255.0

r0(config-if)#int s1/1/0

r0(config-if)#ip add 192.168.23.2 255.255.255.0

r0(config-if)#clo r 64000

r0(config-if)#no sh

%LINK-5-CHANGED: Interface Serial1/1/0, changed state to up

r0(config-if)#^Z

%LINEPROTO-5-UPDOWN: Line protocol on Interface Serial1/1/0, changed state to up

r0#ping 192.168.23.1

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 192.168.23.1, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 2/3/6 ms

r0(config)#ip route 0.0.0.0 0.0.0.0 s1/1/0

r0(config)#

r0(config)#no ip route 0.0.0.0 0.0.0.0 s1/1/0

r0(config)#ip route 2.2.2.2.255.255.255.0 s1/1/0

                    ^

% Invalid input detected at '^' marker.

r0(config)#ip route 2.2.2.2 255.255.255.0 s1/1/0

r0(config)#ip route 3.3.3.3 255.255.255.0 s1/1/0

Press RETURN to get started!

Router(config)#ho r1

r1(config)#no ip domain-loo

r1(config)#lin c 0

r1(config-line)#logg s

r1(config-line)#exec-t

% Incomplete command.

r1(config-line)#exec-t 00

r1(config-line)#exit

r1(config)#int loo 1

r1(config-if)#

r1(config-if)#ip add 2.2.2.2 255.255.255.0

r1(config-if)#exit

r1(config)#int s1/1/1

r1(config-if)#ip add 192.168.12.2 255.255.255.0

r1(config-if)#no sh

%LINK-5-CHANGED: Interface Serial1/1/1, changed state to down

r1(config-if)#no ip add

r1(config-if)#ip add 192.168.23.1 255.255.255.0

r1(config-if)#clo r 64000

r1(config)#int s1/1/0

r1(config)#exit

r1#

r1#ping

r1#ping 192.168.12.1

Sending 5, 100-byte ICMP Echos to 192.168.12.1, timeout is 2 seconds:

%LINK-5-CHANGED: Interface Serial1/1/1, changed state to up

%LINEPROTO-5-UPDOWN: Line protocol on Interface Serial1/1/1, changed state to up

r1#sh ip int b

Interface              IP-Address      OK? Method Status                Protocol

FastEthernet0/0        unassigned      YES manual administratively down down

FastEthernet0/1        unassigned      YES manual administratively down down

FastEthernet1/0        unassigned      YES manual administratively down down

Serial1/1/0            192.168.12.2    YES manual up                    up

Serial1/1/1            192.168.23.1    YES manual up                    up

Loopback1              2.2.2.2         YES manual up                    up

Vlan1                  unassigned      YES manual administratively down down

Protocol [ip]:

Target IP address: 3.3.3.3

Repeat count [5]:

Datagram size [100]:

Timeout in seconds [2]:

Extended commands [n]: y

Source address or interface: 2.2.2.2

Type of service [0]:

Set DF bit in IP header? [no]:

Validate reply data? [no]:

Data pattern [0xABCD]:

Loose, Strict, Record, Timestamp, Verbose[none]:

Sweep range of sizes [n]:

Sending 5, 100-byte ICMP Echos to 3.3.3.3, timeout is 2 seconds:

Packet sent with a source address of 2.2.2.2

.....

Success rate is 0 percent (0/5)

r1#conf t

r1(config)#ip route 1.1.1.1 255.255.255.0 s1/1/0

r1(config)#ip route 3.3.3.3 255.255.255.0 s1/1/1

Target IP address: 1.1.1.1

Sending 5, 100-byte ICMP Echos to 1.1.1.1, timeout is 2 seconds:

Success rate is 100 percent (5/5), round-trip min/avg/max = 4/4/5 ms

Success rate is 100 percent (5/5), round-trip min/avg/max = 2/3/5 ms

Router(config)#ho r2

r2(config)#no ip domain-loo

r2(config)#lin c 0

r2(config-line)#logg s

r2(config-line)#exec-t 00

r2(config-line)#exit

r2(config)#int s1/1/0

r2(config-if)#ip add 192.168.12.1 255.255.255.0

r2(config-if)#clo r 64000

r2(config-if)#no sh

%LINK-5-CHANGED: Interface Serial1/1/0, changed state to down

r2(config-if)#exit

r2(config)#int loo 1

r2(config-if)#

r2(config-if)#ip add 1.1.1.1 255.255.255.0

r2(config)#exit

r2#

r2#sh ip int b

Serial1/1/0            192.168.12.1    YES manual down                  down

Serial1/1/1            unassigned      YES manual administratively down down

Loopback1              1.1.1.1         YES manual up                    up

r2#conf t

r2(config)#ip route 0.0.0.0 0.0.0.0 s1/1/0

r2(config)#

r2(config)#^Z

r2#ping

Target IP address: 2.2.2.2

Source address or interface: 1.1.1.1

Sending 5, 100-byte ICMP Echos to 2.2.2.2, timeout is 2 seconds:

Packet sent with a source address of 1.1.1.1

Serial1/1/0            192.168.12.1    YES manual up                    up

r2(config)#no ip route 0.0.0.0 0.0.0.0 s1/1/0

r2(config)#ip route 1.1.1.1 255.255.255.0

r2(config)#ip route 1.1.1.1 255.255.255.0 s1/1/0

r2(config)#ip route 2.2.2.2 255.255.255.0 s1/1/0

本文轉自gauyanm 51CTO部落格，原文連結：http://blog.51cto.com/gauyanm/234588，如需轉載請自行聯系原作者