Static NAT Configuration Lab

In this lab, you will learn how to configure Static NAT (Network Address Translation) on a router to provide a permanent one-to-one mapping between private and public IP addresses.

Static NAT is an important CCNA topic because it ensures that internal devices can reach external networks using dedicated public IP addresses.

Figure 1 - Static NAT Configuration Topology

This lab will guide you through the configuration, verification, and testing of Static NAT so you understand exactly how the translation process works.

How to Begin

The topology above is already set up for you with all the necessary IP addressing in place.
You can focus entirely on the Static NAT configuration and run every command directly in the integrated CLI below.

Lab Overview

Here’s the structure we will follow throughout this lab:

Step 1 – Configure Static NAT
Step 2 – Test Static NAT Behavior
Step 3 – Clear and Observe the Static NAT Table

Let’s get started!

Before we can begin configuring the Static NAT, we first need to determine the inside and outside NAT interfaces.
In your topology, interface G0/1 is connected to the inside network and G0/0 to the outside network.

Figure 2 - IP NAT Inside and Outside Placement

Configure NAT Roles on the Interfaces

To define the NAT boundary on the router, apply ip nat inside on G0/1 and ip nat outside on G0/0.

R1# conf t
Enter configuration commands, one per line.  End with CNTL/Z.
R1(config)# interface g0/1
R1(config-if)# ip nat inside
R1(config-if)# exit

R1(config)# interface g0/0
R1(config-if)# ip nat outside
R1(config-if)# exit

Now that the NAT roles are configured, we can set up a static NAT entry for each PC in the topology.

We have three inside hosts, so we will create three one-to-one mappings. Each translating a private IP address to a public IP address from the 50.0.0.0/24 range.

Static NAT Mappings

Let’s walk through the first example together.
In the command below, the private address 192.168.1.1 is mapped to the public address 50.0.0.1 whenever traffic leaves toward the outside network:

R1(config)# ip nat inside source static 192.168.1.1 50.0.0.1

This ensures that PC1 always uses 50.0.0.1 as its public identity when accessing external destinations.

We then create the static translations for PC2 and PC3:

R1(config)# ip nat inside source static 192.168.1.2 50.0.0.2
R1(config)# ip nat inside source static 192.168.1.3 50.0.0.3
R1(config)# exit

Verifying the Static NAT Rules

With all three static mappings configured, let’s verify that the router has registered them correctly.
Use the command show ip nat translations

R1# show ip nat translations
Pro  Inside global     Inside local       Outside local      Outside global
---  50.0.0.1          192.168.1.1        ---                ---
---  50.0.0.2          192.168.1.2        ---                ---
---  50.0.0.3          192.168.1.3        ---                ---

These entries confirm that each private IP address has a permanent one-to-one relationship with its public address.
They appear immediately, even before any traffic is sent, which is one of the key characteristics of Static NAT.

To get additional information, you can also run show ip nat statistics:

R1# show ip nat statistics
Total translations: 3 (3 static, 0 dynamic, 0 extended)
Outside Interfaces: GigabitEthernet0/0
Inside Interfaces: GigabitEthernet0/1
Hits: 0  Misses: 0
Expired translations: 0
Dynamic mappings:

This output confirms: