[Phys-l] IP address

[Ludwik Kowalski <kowalskil@mail.montclair.edu>]

I just learned how to get the current IP address of a computer 
connected to Internet. It is simply a matter of using a browser and 
typing this URL

http://www.whatismyip.com

For some reason the IP address I got form my Mac (OS-10.3) was not 
correct. Is it my Mac only? To get the IP address from my Mac I do 
this:

a) select SYSTEM PREFERENCES from the APPLE menu
b) click on the NETWRK icon
c) The IP address appears in the selected line labeled "built in 
ethernet."

But that address was not recognized as valid by a server I wanted to 
access using the FTP. The address I got from the above URL, however, 
was recognized as valid. What causes the discrepancy? Do other Mac 
users (OS-10-3 only? Mac only?) have the same IP address by two 
methods?

Ludwik Kowalski
Let the perfect not be the enemy of the good.