CONFIGURE NAT OVERLOAD - PAT (PORT ADDRESS TRANSLATION) ON A CISCO ROUTER

R1# configure terminal
R1(config)# interface fastethernet0/0
R1(config-if)# ip nat inside
R1(config-if)# interface serial0/0
R1(config-if)# ip nat outside
R1(config-if)# exit
R1(config)# access-list 100 remark == [Control NAT Service]==
R1(config)# access-list 100 permit ip 192.168.0.0 0.0.0.255 any
R1(config)# ip nat inside source list 100 interface serial 0/0 overload

R1# show ip nat translations
Pro Inside global           Inside local            Outside local         Outside global
udp 200.2.2.1:53427  192.168.0.6:53427      74.200.84.4:53        74.200.84.4:53
udp 200.2.2.1:53427  192.168.0.6:53427      195.170.0.1:53        195.170.0.1:53
tcp 200.2.2.1:53638   192.168.0.6:53638      64.233.189.99:80    64.233.189.99:80
tcp 200.2.2.1:57585   192.168.0.7:57585      69.65.106.48:110    69.65.106.48:110
tcp 200.2.2.1:57586   192.168.0.7:57586      69.65.106.48:110    69.65.106.48:110

R1# clear ip nat translation *

R1# show ip nat translations
Pro Inside global ...........Inside local .....Outside local .......Outside global

R1# show ip nat statistics
Total active translations: 200 (0 static, 200 dynamic; 200 extended)
Outside interfaces:
Serial 0/0
Inside interfaces:
FastEthernet0/0
Hits: 163134904 Misses: 0
CEF Translated packets: 161396861, CEF Punted packets: 3465356
Expired translations: 2453616
Dynamic mappings:
-- Inside Source
[Id: 2] access-list 100 interface serial 0/0 refcount 195
Appl doors: 0
Normal doors: 0
Queued Packets: 0a



From http://www.firewall.cx/cisco-technical-knowledgebase/cisco-routers/260-cisco-router-nat-overload.html