[NBLUG/talk] Networking question

ME dugan at passwall.com
Mon Sep 29 11:22:13 PDT 2003


Steve Johnson said:
> Kyle Rankin wrote:
>> On Sun, Sep 28, 2003 at 03:27:26PM -0400, Dave Sisley wrote:
>
>> Basically what you want to do is set up IP Masquerading (or possibly
>> NAT)
>
> I always thought NAT and IP Masq were the same thing, just different
> names for the same idea.
> Can anyone explain what the difference is?

NAT is a general set of many kinds of NAT (One to one, One to Many, Some
to many, Many to Many, All to All, etc)

IP Masquerading is often viewed as a subset of NAT (One to Many)

Where would Many to Many or All to All be used? Say you have 253 IP
addresses but you want to filter them all and hide the true IP addresses
of your hosts while still permitting each host to accept incomming
connections. Then you can map the 253 IP addresses on the Internet to 253
private IP addresses and make sure your NAT both ways for each IP to
another private IP.

So Masqerading can be viewed as a kind of NAT, but the purist would likely
say not all NAT is Masquerading.

HTH,
-ME





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