一：实验拓扑:
2:实验配置：
int f0/0
ip add 192.168.0.1 255.255.255.0
no sh
ip nat inside
int s2/2
ip add 1.1.1.1 255.255.255.0
ip nat outside
access-list 1 permit 192.168.0.0 255.255.255.0
ip nat inside source list 1 interface s2/2 overload
===================================================
ip dhcp pool VLAN1
network 192.168.0.0 255.255.255.0
default-router 192.168.0.1
dns-server 61.134.1.4
domain-name my3377.com
lease infinite
ip dhcp excluded-address 192.168.0.1
R1#
interface FastEthernet0/0
ip address dhcp
R3#
interface Serial2/1
ip address 1.1.1.2 255.255.255.0
R1#show ip int b
Interface IP-Address OK? Method Status Protocol
FastEthernet0/0 192.168.0.2 YES DHCP up up
Serial2/0 unassigned YES unset administratively down down
R1#ping 1.1.1.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 1.1.1.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 8/43/124 ms
R3#debug ip packet
IP packet debugging is on
R3#
*Oct 7 17:05:10.959: IP: tableid=0, s=1.1.1.1 (Serial2/1), d=1.1.1.2 (Serial2/1), routed via RIB
*Oct 7 17:05:10.963: IP: s=1.1.1.1 (Serial2/1), d=1.1.1.2 (Serial2/1), len 100, rcvd 3
*Oct 7 17:05:10.963: IP: tableid=0, s=1.1.1.2 (local), d=1.1.1.1 (Serial2/1), routed via FIB
*Oct 7 17:05:10.967: IP: s=1.1.1.2 (local), d=1.1.1.1 (Serial2/1), len 100, sending
*Oct 7 17:05:11.015: IP: tableid=0, s=1.1.1.1 (Serial2/1), d=1.1.1.2 (Serial2/1), routed via RIB
*Oct 7 17:05:11.019: IP: s=1.1.1.1 (Serial2/1), d=1.1.1.2 (Serial2/1), len 100, rcvd 3
*Oct 7 17:05:11.019: IP: tableid=0, s=1.1.1.2 (local), d=1.1.1.1 (Serial2/1), routed via FIB
*Oct 7 17:05:11.023: IP: s=1.1.1.2 (local), d=1.1.1.1 (Serial2/1), len 100, sending
*Oct 7 17:05:11.059: IP: tableid=0, s=1.1.1.1 (Serial2/1), d=1.1.1.2 (Serial2/1), routed via RIB
*Oct 7 17:05:11.063: IP: s=1.1.1.1 (Serial2/1), d=1.1.1.2 (Serial2/1), len 100, rcvd 3
*Oct 7 17:05:11.063: IP: tableid=0, s=1.1.1.2 (local), d=1.1.1.1 (Seri
R3#al2/1), routed via FIB
*Oct 7 17:05:11.063: IP: s=1.1.1.2 (local), d=1.1.1.1 (Serial2/1), len 100, sending
*Oct 7 17:05:11.071: IP: tableid=0, s=1.1.1.1 (Serial2/1), d=1.1.1.2 (Serial2/1), routed via RIB
*Oct 7 17:05:11.075: IP: s=1.1.1.1 (Serial2/1), d=1.1.1.2 (Serial2/1), len 100, rcvd 3
*Oct 7 17:05:11.075: IP: tableid=0, s=1.1.1.2 (local), d=1.1.1.1 (Serial2/1), routed via FIB
*Oct 7 17:05:11.075: IP: s=1.1.1.2 (local), d=1.1.1.1 (Serial2/1), len 100, sending
*Oct 7 17:05:11.083: IP: tableid=0, s=1.1.1.1 (Serial2/1), d=1.1.1.2 (Serial2/1), routed via RIB
*Oct 7 17:05:11.087: IP: s=1.1.1.1 (Serial2/1), d=1.1.1.2 (Serial2/1), len 100, rcvd 3
*Oct 7 17:05:11.087: IP: tableid=0, s=1.1.1.2 (local), d=1.1.1.1 (Serial2/1), routed via FIB
*Oct 7 17:05:11.087: IP: s=1.1.1.2 (local), d=1.1.1.1 (Serial2/1), len 100, sending
R2#show ip nat translations
Pro Inside global Inside local Outside local Outside global
icmp 1.1.1.1:9 192.168.0.2:9 1.1.1.2:9 1.1.1.2:9
