1. Network Address Translation
NAT
IP Public
Internet
Many-to-one
PAT
IP
IP
IP
IP
IP
IP Public
IP Public
IP Public
IP Public
One-to-one
Static NAT
Dynamic NAT
3. NAT
Internet
10.0.0.0/24
.1 .2 2.2.2.2
.1
1.1.1.0/24
.4
data 10.0.0.1 2.2.2.2 data 1.1.1.1 2.2.2.2
data 1.1.1.1
2.2.2.2
NAT Table
Inside Outside
10.0.0.1 1.1.1.1
data 1.1.1.1 2.2.2.2
10.0.0.1
data 1.1.1.1
2.2.2.2 10.0.0.1
Router# show ip nat translations
Inside global Inside local Outside local Outside global
1.1.1.1 10.0.0.1 ... ...
Router#
4. Static NAT
NAT
Internet
10.0.0.0/24
.1 .2 2.2.2.2
.1
1.1.1.0/24
.4
data 1.1.1.1
2.2.2.2
NAT Table
Inside Outside
10.0.0.1 1.1.1.1
data 1.1.1.1
2.2.2.2 10.0.0.1
Web
Server
R(config)# ip nat inside source static 10.0.0.1 1.1.1.1
R(config-if)# ip nat inside
R(config-if)# ip nat outside
5. Static NAT
NAT
Internet
10.0.0.0/24
.1 .2 2.2.2.2
.1
1.1.1.0/24
.4
data 3.3.3.3
2.2.2.2
NAT Table
Inside Outside
10.0.0.1 3.3.3.3
data 3.3.3.3
2.2.2.2 10.0.0.1
Web
Server
R(config)# ip nat inside source static 10.0.0.1 3.3.3.3
R(config)# ip route 3.3.3.3 255.255.255.255 1.1.1.1
front IP, routed IP