Network Address Translation - NAT

Network Address Translation - NAT

(Static)

Network Address Translation is a feature to modify the Network address information, it is basically mapping feature which is mapped one IP address to another.

Syntax to implement NAT on Router

Syntax:

Router(config)#interface <type> <no>

Router(config-if)#ip NAT inside
This command need to be given on interface where LAN (Private) Network is present

Router(config-if)#ip NAT outside 
This command need to be given on interface where WAN (Private) Network is present

Syntax for configuring static NAT is as Follows:
Router(config)#ip nat inside source static <Private IP> <Public IP>

Configuration of static NAT:

Delhi#conf t

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

Delhi(config)#

Delhi(config)#interface serial 0/0/1

Delhi(config-if)#ip address 201.2.0.15 255.255.255.248

Delhi(config-if)#no shut

%LINK-5-CHANGED: Interface Serial0/0/1, changed state to up

Delhi(config-if)#

Delhi(config-if)#encapsulation ppp

Delhi(config-if)#ip nat outside

Delhi(config-if)#exit

Delhi(config)#

Delhi(config)#interface fastEthernet 0/0

Delhi(config-if)#ip nat inside

Delhi(config-if)#exit

Delhi(config)#ip nat inside source static 192.168.1.20 201.2.0.16

Delhi(config)#exit

Delhi#

Show command:

Delhi#sh ip nat translation

Delhi#debug ip nat

Verify the output using following commands:

OUTPUT:

Delhi#sh ip nat translations 

Pro     Inside global        Inside local       Outside local      Outside global

---        201.2.0.16        192.168.1.20           ---                       ---

Delhi#debug ip nat

IP NAT debugging is on

Delhi#