On Sun, Mar 12, 2000 at 03:46:20AM -0500, James Sharp wrote:
> Most cable modem systems are shared media.  Think of it as one big piece
> of 10Base-2 coax.  Some cable providers program their modems to filter out
> simple stuff, like NetBIOS over IP...mainly to keep all the windows users
> from sniffing each other's shares.  But you can sit on your local cable
> modem and watch traffic from everyone else.

Also, some cable modems only allow one entry in their ARP tables - by design,
or by configuration. If you plug such a modem into a hub, you may find that
the computer running NAT can't talk to it because it has decided to learn
some other device's Mac address. Best to have two network interfaces on a
box, one in, one out, so the 'out' and the Cable modem an have a segment
to themselves.

-- 
David Maxwell, david@vex.net|david@maxwell.net --> Although some of you out
there might find a microwave oven controlled by a Unix system an attractive
idea, controlling a microwave oven is easily accomplished with the smallest
of microcontrollers. - Russ Hersch - (Microcontroller primer and FAQ)