Question about IP masqing

[Willem <wsa@hotpop.com>]

Hi,

I'm trying to get to grips with all the network stuff.
I'm still using a script from the net cause i don't feel 
confident enough to build my own yet...

But one thing keeps illuding me.
with MASQ..if a client on the local LAN makes a connection it
will appear on the other side as if the linux/server is actually
making the connection....so the server IP is visible...
But i recall reading somewhere that the guys from freshmeat
said that xx%...i think it was 80 orso...of the hits were from
masqueraded addresses.
Now how the hell can they tell?...because i thought 
only the server' sIP is supposed to show up....
I assume it has something to do with analyzing what's inside
a packet but does this also mean they can figure out the
internal IP behind the 'real' IP from which the packet is
originating?

enlighten me:)

Cheerios