"These Two devices are natted" = What does that mean?

Posted on 2013-12-18
Last Modified: 2013-12-22
What does it mean when two devices are natted?
I know that a router uses NAT to allow devices from outside the company to communicate to devices inside the company.  But I read a piece of documentation discussing two devices INSIDE of the company that are natted.  Why should two devices inside the company require NATTING?
Question by:brothertruffle880
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
  • 2
LVL 44

Accepted Solution

Darr247 earned 250 total points
ID: 39728310
Network Address Translation might need to occur anytime more than one subnet exists inside the company.

Even in the same computer, if Internet Connection Sharing is being used, NAT would occur between the 2 network adapters involved in the sharing.
LVL 11

Assisted Solution

Miftaul earned 250 total points
ID: 39728420
NAT is not required between the subnets if they are in private IP block RFC1318. As long as the routing is there, no NAT required.

NAT is required only when we have private IP and we want to communicate with the public internet IPs.

But in very few scenarios, NAT is done within the company subnets. Say you have a merger, your local internal subnet and the remote site internal subnet overlaps in a site to site connectivity.

eg, your office-a subnet and office-B subnet overlaps. You have to have NAT over VPN.
LVL 44

Assisted Solution

Darr247 earned 250 total points
ID: 39730511
If you work for a large company that was on the networked bandwagon early, such as HP, GM or IBM, nearly all their internal (L2) switches/routers/et al have public IPs (HP had an entire /8 public IPv4 block the last I knew), but they also have lots of different private IP subnets inside various buildings/plants where NAT'ing happens.  That's why I said, *might* need to occur.  :)
LVL 11

Assisted Solution

Miftaul earned 250 total points
ID: 39731249
I agree with you. the word *might* flipped your whole sentence to me, my mistake.

But the possibility of internal NAT is very limited now a days.

The place I am with happens to use Public block of IPs for individual devices including workstations. We also have private block of IP within the network, we hardly do NAT within LAN, rather solely use routing internally.

NAT is only done at the edge when traffic is destined for internet.

Featured Post

Free Tool: Postgres Monitoring System

A PHP and Perl based system to collect and display usage statistics from PostgreSQL databases.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Getting hacked is no longer a matter or "if you get hacked" — the 2016 cyber threat landscape is now titled "when you get hacked." When it happens — will you be proactive, or reactive?
Shadow IT is coming out of the shadows as more businesses are choosing cloud-based applications. It is now a multi-cloud world for most organizations. Simultaneously, most businesses have yet to consolidate with one cloud provider or define an offic…
Viewers will learn how to properly install and use Secure Shell (SSH) to work on projects or homework remotely. Download Secure Shell: Follow basic installation instructions: Open Secure Shell and use "Quick Connect" to enter credentials includi…
After creating this article (, I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…

735 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question