Differences between TCP/IP with and without NAT

[jspsh]

What is the primary difference between those two?

 

[JackMDS]

Let say you have a Big apartment building in the USA with a Doorman.

When a visitor comes to visit some one in the building he speaks to the doorman in English.

For Network the English his TCP/IP.

The doorman main job his to send the visitor to the right apartment, this action is NAT (Network Address Translation).

So the Building is the Network.

Traffic on the Network speaks TCP/IP, and NAT sends the Internet traffic to the computer on the Network that it meant for.

Link to: AnandTech - FAQ. Basic Options for Internet Connection Sharing

Link to: Cable/DSL Routers - NAT & Ports.

:sun:

 

[jspsh]

Oops, I forgot to specify, I mean to say what is the difference between the packets.

 

[polm]

Originally posted by: jspsh
Oops, I forgot to specify, I mean to say what is the difference between the packets.

basically, just address modifications in the header. Checksum as well, I think.

 

[Nothinman]

basically, just address modifications in the header. Checksum as well, I think.

Just to clarify address in this case means the address and the port. That and the TTL _should_ be decremented by the NAT/PAT device, but I can think of a few ways to avoid that.