NAT confusion

xkaijinx

On this image, I wanted to point out each of the NAT addresses to see if I am correct on this, and confused on the last portion.

Inside Global - 22.23.24.25
Outside Global - 15.16.17.18
Inside Local - 192.168.1.22
Outside Local - ??


I understand the definition of the above, just having issues applying it.

Inside Global - Local host, external address
Outside Global - External host, external address
Inside Local - Local host, internal address
Outside Local - External host, internal address

Zartanasaurus

You have the first 3 right, so the 4th should be obvious

Inside Global > Your IP address as seen by the public.
Inside Local > Your local IP address not seen by the public.
Outside Global > The public IP of your destination.
Outside Local > The inside IP of your destination (normally unused).

xkaijinx

Right, I figured that. But can you lay it out in a more conceivable way?

The outside local is basically the default gateway for whichever LAN?

Zartanasaurus

xkaijinx wrote: »

Right, I figured that. But can you lay it out in a more conceivable way?

The outside local is basically the default gateway for whichever LAN?

Well, your router is performing NAT for your inside hosts so the public internet can see them. That's the inside global and the usual purpose of NAT.
However, if you wanted to hide the outside internet (or just another network) you can configure the router to NAT outside addresses so they appear like local networks.

iamme4eva

What zartan said....

For example, you could do NAT so that when you ping 10.0.0.10 it translates to 173.194.41.137 (google.com). Your hosts never know they have been on the internet.

Never seen a use for it, but it's there.

dsgm

Glad i found this, this was doing my head in, reading different explanations didnt help, thanks much