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).

>>5
since it's a router, it has dhcp built into it.
I see, I thought that was somewhere inside the ISP's network.
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.
Wouldn't my modem work as a router (this is my original question)?
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.
Well, they give me at least four IPs.
- learn linux - get an old computer (500Mhz+) - install two network cards - learn how to set it up as a router/firewall
I've got one running OpenBSD (333MHz and 64MB RAM, need to get a second NIC though, or perhaps two gigabit NICs instead, 100MB is excruciatingly slow in a LAN... hm, one gigabit NIC is enough) -- could I use that one just as a firewall and let my modem handle the routing?