Networking question

Could I set my network up like this?:
  Modem -- Switch -- Computers
My current setup is like this:
  Modem -- [Computer, Router -- Computers]

What I really wonder is if DHCP will work with several computers on the same port on the modem (which has four ports).  If I had a switch I could try this of course, but the case is that I do not have one (and I do not think I could configure my router into being a switch).

[sigh]
if your modem has four ports (i'll bet it has five), it's a modem/router/switch all in one.

 the four ports are ones you're supposed to hook your computers into.  the fifth port, labeled Internet or WAN, is what your dsl goes into (you probably don't have cable).

 since it's a router, it has dhcp built into it.

 dhcp will work with all your computers.  the job of dhcp is to hand out free ip addresses to computers who ask for it (they do if you tell it to "Automatically get IP address" in the Network Connection control panel).  dhcp will hand out as many addresses as you tell it that it may.  you probably can't configure this aspect of dhcp on your hardware router though, but still, it should take care of it.

 check your device configuration for something called "bridged mode", that would effectively turn off the router part.  i don't think you can do that since yours is also a built in switch, and you need a router before the switch for anything to work.

 let me tell you this too: as long as your ISP gives you only one IP, there is no way to give computers behind it their own global, external IPs.

 but i recommend that you need to do the following:

 - learn linux
 - get an old computer (500Mhz+)
 - install two network cards
 - learn how to set it up as a router/firewall