Networking question

[Panella]

So, before I do something moronic and buy the wrong thing, can someone explain the difference between a router and a switch? I'm trying to hook up 3 computers to the internet from the ethernet port in my room but not really sure which option I should be going with. I'm pretty sure I need a router to do it but they seem to be quite a bit more expensive, so if I could get away with just a switch it would be lovely.

My apartment just has ethernet ports in the walls instead of an actual modem if that makes a difference. Also, I'm specifically looking for a wired only option if anyone has any suggestions.

[Cyn]

You need a router.

[Killgannon]

ok

a router can tell where data comes from / where it needs to go... so pc one sends out data, the router realizes pc1 sent out that data, and sends the data that comes back, back to pc1, and so on with pc2 and 3

a switch cannot tell, its basically gonna send data on through your modem, and the data that comes back is gonna be sent back to EVERY pc, which will cause disconnects and other problems...

unless your modem has routing functions (highly doubtful unless it says it does...) you need a router.

[levish]

more specifically what you want i believe is called a "gateway (cable/dsl) router with built in switch" they can also be had with built in wireless connectivity in addition to ethernet and are not much more expensive than a plain old home user switch

[Fallso]

Switches are generally for connecting other devices to it then connecting the switch to a router (it's for larger networking purposes).

Some modems are combis now, like the BT home hub which is a router and modem. You should be able to pick up a linksys router or belkin router for no more than about $60 though.

[Dolmen]

http://en.wikipedia.org/wiki/Network_switch

Switches are nice, but you can always get a router/switch combo. Hubs flood the network, and switches send the information to only the intended target, so stay from hubs (if they even sell them anymore). If you utilize your local network a lot, buy a gb switch as the gateway from your router to your local network.

[Niya]

My apartment just has ethernet ports in the walls instead of an actual modem if that makes a difference.

Um... short question about that. Are you really sure that it's an ethernet (RJ45, google it if you're not sure) port in your wall?
In case it's really RJ45, that would probably mean that it's only the end of a patch cable and that the other end goes to a central server/switching room.
And another question. When you connect only 1 PC, do you have to set up dialing or does it just work?

when "it just works", a switch is enough.
a switch just keeps a table with the names (read: MAC adresses) of all connected computers and distributes network packages according to this table.

when you need to dial, you'll need a router with an includes switch (wich pretty much any router has nowadays)
a router is used to connect networks with different IP ranges. Most private networks have the 192.168.*.* range, and your interner provider "owns" another IP range (let's say 82.*.*.*). the router just checks the destination IP range, looks up if that one's connected to it, and forwards packages to the appropriate port.
another important function of a router is NAT (network adress translation). meaning: when your computer sends a request to a server on the net, the router remembers that destination and overwrites the sender (local IP adress of your PC) with the IP your internet provider assigned to you. when the requested server answers, the router "remembers" that your PC sent the request and forwards the packages to you. this is needed when more than 1 PC connects to the internet over one router, without it communication with internet servers would be impossible because your local IP adress as the destination IP is not routable (how should any router be able to determine the right destination when there are millions of 192.168.* networks worldwide? )

[Panella]

My apartment just has ethernet ports in the walls instead of an actual modem if that makes a difference.

Um... short question about that. Are you really sure that it's an ethernet (RJ45, google it if you're not sure) port in your wall?
In case it's really RJ45, that would probably mean that it's only the end of a patch cable and that the other end goes to a central server/switching room.
And another question. When you connect only 1 PC, do you have to set up dialing or does it just work?

when "it just works", a switch is enough.
a switch just keeps a table with the names (read: MAC adresses) of all connected computers and distributes network packages according to this table.

Yep, pretty sure it's an ethernet port. "it just works" when I plug it in.

Thanks for the replies. I was pretty sure I needed a router but was curious about the switch option since I've only ever used routers.