The CCNA Basic: Static NAT

CCNA 200-301

CCNP Enterprise

CCNP Security

CCIE Enterprise Lab

CCIE Security Lab

CCNP Service Provider

CCNP Data Center

CCNP Collaboration

CCIE DC Lab

2019-12-20

Using static NAT, a router or firewall converts a private IP address to a public IP address. Each private IP address is mapped to a public IP address. Static NAT is not often used because each private IP address requires a public IP address.

To configure static NAT, three steps are required:

1.Configure private/public IP address mapping by using IP nat in the source static PRIVATE_IP PUBLIC_IP command

2. Configure the internal interfaces of the router using the IP nat inside command

3. Configure the external interface of the router using the IP nat outside command

Here is an example:

Computer A requests the Web resource to S1. When sending a request to router R1, computer A uses its private IP address. Router R1 receives a request, changes the private IP address to a public IP address, and then sends the request to S1. S1 in response to R1. R1 receives a response, finds and changes the target IP address to a private IP address of Computer A in its NAT table.

In the above example, we need to configure static NAT. To do this, the following command is required on R1:

Using the above command, we configure a static mapping between the dedicated IP address 10.0.0.2 of computer A and the R1 common IP address 59.50.50.1 of the router. To check NAT, you can use the show IP nat translations command:

Notice that SPOTO will update the CCNA technical articles. If you are interested in this, and you can follow SPOTO. Besides, SPOTO is addicted to training in Cisco certification exams. if you have any questions, and you also can enquire for us!