用SNAT實現多條鏈路的地址轉換功能！

1. 做業要求：

實現SNAT 功能 利用基於端口的NAPT方法來彌補IP不夠用不能上網的缺陷！

2. 拓撲圖以下：

3.配置及必要的說明信息：

R1(config)#int f0/0

R1(config-if)#ip add 192.168.3.1 255.255.255.0

R1(config-if)#no shut

用的是Host-only 到Vmware1 一臺PC

R1(config)#int s1/0

R1(config-if)#ip add 192.168.4.2 255.255.255.0

R1(config-if)#no shut

R1(config-if)#int s1/1

R1(config-if)#ip add 192.168.5.2 255.255.255.0

R1(config-if)#no shut

R2(config)#int s1/0

R2(config-if)#ip add 192.168.4.1 255.255.255.0

R2(config-if)#no shut

R2(config-if)#int loopback 1

R2(config-if)#ip add 192.168.1.1 255.255.255.0

R3(config)#int s1/1

R3(config-if)#ip add 192.168.5.1 255.255.255.0

R3(config-if)#no shut

R3(config-if)#int f

R3(config-if)#int f0/0

R3(config-if)#ip add 192.168.2.1 255.255.255.0

R3(config-if)#no shut

R1#ping 192.168.5.1

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 192.168.5.1, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 32/36/56 ms

R1#ping 192.168.4.1

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 192.168.4.1, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 32/52/80 ms

橋接到本地鏈接!

C:\Documents and Settings\Administrator>ipconfig /all

R1(config)#ip route 192.168.1.0 255.255.255.0 192.168.4.1

R1(config)#ip route 192.168.2.0 255.255.255.0 192.168.5.1

R1(config)#int f0/0

R1(config-if)#ip nat inside

R1(config-if)#int s1/0

R1(config-if)#ip nat outside

R1(config-if)#int s1/1

R1(config-if)#ip nat outside

R1(config-if)#end

R1(config)#access-list 101 permit ip 192.168.3.0 0.0.0.255 192.168.1.0 0.0.0.255

R1(config)#access-list 102 permit ip 192.168.3.0 0.0.0.255 192.168.2.0 0.0.0.255

R1(config)#ip nat inside source list 101 interface s1/0 overload

R1(config)#ip nat inside source list 102 interface s1/1 overload

4.測試：

Window server2003

開啓遠程桌面：

X p 做爲192.168.3.0 網段的一臺PC

開始-------運行 輸入：mstsc

R1#show ip nat translations

Pro Inside global Inside local Outside local Outside global

tcp 192.168.5.2:1102 192.168.3.10:1102 192.168.2.12:3389 192.168.2.12:3389

tcp 192.168.5.2:1103 192.168.3.10:1103 192.168.2.12:3389 192.168.2.12:3389

R1#show ip nat translations

Pro Inside global Inside local Outside local Outside global

icmp 192.168.4.2:512 192.168.3.10:512 192.168.1.1:512 192.168.1.1:512

icmp 192.168.5.2:512 192.168.3.10:512 192.168.2.1:512 192.168.2.1:512

icmp 192.168.5.2:512 192.168.3.10:512 192.168.2.12:512 192.168.2.12:512

爲了便於理解,附加上此圖!