[NCLUG] Question on Cable modems

[Chad Perrin]

On Fri, Apr 28, 2006 at 10:38:52PM +0000, bsimpson at att.net wrote:
> In my current residence I have cable Internet utilizing
> a cable modem with a single ethernet output port connected
> to my PC.  I would like to connect up a second computer.
> In this case, would a hub or switch work just as well as
> a router, connected between the modem and the PCs?  I
> presume that if I use a hub that the modem would act as
> a DHCP server to both PCs, or are they configured to talk
> to only one PC?  In that case I assume I must use a router?
> I would like a little clarification on this before I
> purchase something that may be more than I need, or
> inadequate...

Unless your cable modem is also a router, that's not likely to work.  A
hub would allow your computers to talk to each other, and would likely
allow exactly one computer to connect to the Internet at a time, and
that's it.  I'm not entirely sure what would happen with a switch, but
you'd be querying a Comcast (or other ISP) DHCP server with both
computers, and most ISPs don't like to hand out multiple IP addresses to
one cable modem.  As such, I'm sure it would fail pretty spectacularly.

You really do need a router, I think.

-- 
Chad Perrin [ CCD CopyWrite | http://ccd.apotheon.org ]
"Real ugliness is not harsh-looking syntax, but having to
build programs out of the wrong concepts." - Paul Graham