Cisco Config Lab4: Static NAT

This is the fourth post in a series of posts providing step-by-step instructions that need to be followed in order to solve the labs proposed by Wendell Odom, the author of the books:

1. CCNA 200-301 Official Cert Guide, Volume 1

2. CCNA 200-301 Official Cert Guide, Volume 2

If you want to follow along, you can find the lab requirements and the .pkt file on Wendell’s blog.

Gulian Technology
Gulian Technology

You can download the Packet Tracer from Cisco Networking Academy.

You can find the third post here.

In this lab, we need to configure static NAT (Network Address Translation) on a Cisco router.

These are the steps we need to take:

  1. Configure S1 to use the 172.16.1.10 as an inside global address.
  2. Configure S2 to use the 172.16.1.20 as an inside global address.
  3. Configure S3 to use the 172.16.1.30 as an inside global address.
  4. Configure a static route for the CIDR 172.16.1.0/24 on R2.
  5. Check that static NAT is working as intended.

Check that the initial configuration is in place

Here is the network diagram used in this lab:

Network diagram
Network diagram

In the first step, I will check the initial configuration of the routers.

R1 initial config
R1 initial config
R2 initial config
R2 initial config

Configure static NAT on R1

In order to configure static network address translations we need to run the following commands on R1. Here, we are performing a static mapping between the host IP address (S1, S2, S3) and its inside global address.

ip nat inside source static 192.168.1.10 172.16.1.10
ip nat inside source static 192.168.1.20 172.16.1.20
ip nat inside source static 192.168.1.30 172.16.1.30
Define the static mapping between the host IP address and its inside global address
Define the static mapping between the host IP address and its inside global address

Next, we need to identify the interfaces for which the static NAT will take place.

The following commands should be added on router R1:


# under interface gig0/1
ip nat inside 

#under interface gig0/2
ip nat outside
Identify the needed interfaces for static NAT
Identify the needed interfaces for static NAT

Configure static route on router R2

Next, we need to configure the static route on R2 for the returning traffic. Without this route, there will be no communication between PC S1 and the Router R2.

ip route 172.16.1.0 255.255.255.0 10.10.10.1
Configure the static route on R2
Configure the static route on R2

After configuring the static route, we need to verify that it was added to the routing table.

show ip route
Check the routing table on R2
Check the routing table on R2

Check that static NAT is working as intended

The last step is to verify the connectivity and ensure that static NAT is working as expected.

ping 10.10.10.2
Test connectivity from PC S1 to router R2
Test connectivity from PC S1 to router R2

Now, we need to check if there are any translations on the router R1.

show ip nat translations
show ip nat statistics 
Check ip nat translations and statistics
Check ip nat translations and statistics

I hope you find this post helpful.

If you struggle to configure static NAT, share your issue in the comments and I will try to help you.

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