This is the second 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.
You can find the first post here.
In this lab, we need to configure interface PAT (Port Address Translation) on a Cisco router.
These are the steps we need to take:
- Identify the hosts for which port address translations should take place (In our lab these are S1, S2 and S3).
- Configure interface PAT on R1.
- Configure a static route on R2.
- Check that interface PAT is working as intended.
Check that the initial configuration is in place
Here is the network diagram used in this lab:
In the first step, I will check the initial configuration of the routers.
Configure the numbered access list (ACL) on router R1
In order to identify the hosts for which the address translations should take place, we need to configure a numbered access list on R1.
access-list 1 permit 184.108.40.206 0.0.0.255
Configure interface PAT on router R1
Now, we need to configure the interface PAT on the Cisco router R1, and specify the inside and outside interfaces for which PAT should be performed.
ip nat inside source list 1 interface gig0/2 overload # under interface gig0/1 ip nat inside #under interface gig0/2 ip nat outside
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 220.127.116.11 255.255.255.0 10.20.30.1
After configuring the static route, we need to verify that it was added to the routing table.
show ip route
Check that interface PAT is working as intended
The last step is to verify the connectivity and ensure that PAT is working as expected.
Now, we need to check if there are any translations on the router R1.
show ip nat translations show ip nat statistics show ip access-lists
I hope you find this post helpful.
If you struggle to configure PAT, share your issue in the comments and I will try to help you.