NAT and PAT

Tricon7

For those of you who have already learned all this, is it hard to finally "get down" NAT and PAT? We just covered it for the first time today in class, and with all the commands, including ACLs, IP pools, ip routes, etc, etc, I know it may take me a while to pound it all in my head. Is NAT/PAT one of the harder topics to tackle in CCNA (like subnetting), or is it just daunting for me?

tech-airman

Tricon7 wrote:

For those of you who have already learned all this, is it hard to finally "get down" NAT and PAT? We just covered it for the first time today in class, and with all the commands, including ACLs, IP pools, ip routes, etc, etc, I know it may take me a while to pound it all in my head. Is NAT/PAT one of the harder topics to tackle in CCNA (like subnetting), or is it just daunting for me?

Tricon7,

Let me help you by separating "NAT/PAT" into three types:

1. Static NAT
2. Dynamic NAT
3. PAT

Is this helping?

redgoblin

Actually I found NAT & PAT to be one of the more straightforward topics once you get your head around the terminology involved (inside, outside, global, local etc).

First step I always do is to specify which interfaces are 'nat inside' and which are 'nat outside'

Then the syntax is as following, assuming your inside local is 192.168.1.1 and you want to translate to 82.32.4.56:

Static: ip nat inside source static 192.168.1.1 82.32.4.56

Dynamic: ip nat inside source list 1 pool REDGOBLIN
access-list 1 permit 192.168.1.0 0.0.0.255
ip nat pool REDGOBLIN 82.32.4.56 82.32.4.56 netmask 255.255.255.0

PAT: same syntax as 'dynamic' but with the keyword 'overload' after the netmask part.

And thats all there is!

Netstudent

I found Nat/PAT to be easy as well. Once you know what you are actually doing, it is very straightforward, as redgoblin said. The only time I could see it getting kinda hairy is if you were overlapping subnets and using inside locals/globals as well as outside locals/globals.

I did have to read the detailed definitions of inside and outside locals and globals about 4 or 5 times.
Just because the way Odom explained them, it was kinda confusing. But the config is simple.

But don't feel bad if it doesn't immediately click. Some things click with some people and don't click with others.