Help me set up this network...

Factual Questions
1

I’m a Mac user who has just purchased a Windows laptop, and I’m trying, unsuccessfully, to get both of them online at the same time.

The Mac: iMac running Mac OS X 10.7.3 (Lion)

The PC: Toshiba laptop running Windows 7

The Internet Connection: Charter Cable Internet

Between the cable modem and the two computers is a 5-slot ethernet hub.

Before I go any further, I want to mention that I have networked a Mac and a Windows PC into the same Internet connection several times in the past, with the computers in question running varying flavors of the Mac OS (ranging from Mac OS 8 to the current Lion) and Windows (98, XP, and 7). And I’ve never had any difficulty with it:

• Connect incoming ethernet cable to hub
• Connect both computers to hub
• Boot both machines
• Connect to Internet with both machines.

I’ve done this via ISDN, DSL, and my local PUD’s fiber optic Internet system. However, this is the first time I’ve tried it with Charter Cable Internet.

I didn’t pick up a second ethernet cable until a couple hours ago, so in order to connect the laptop I had to disconnect my iMac from the cable modem, connect the laptop to the modem, power down the modem (by unplugging it), wait 10 seconds, power the modem back up, and then boot the laptop. Then repeat that process to switch back to the iMac. Pain in the neck.

But now I have the second ethernet cable, and have both machines connected to the ethernet hub. But for unknown reasons, I cannot get both machines to connect to the Internet at the same time. It seems to be a matter of whichever machine boots up first gets the connection, and the other one is out of luck. I’ve gone through multiple reboots of both machines, rebooting the modem, “rebooting” the ethernet hub, booting the computers in different orders, booting them simultaneously, etc, etc.

It’s kind of looking to me like that cable modem doesn’t know what to do with two computers connected to it. Am I going to need a router, rather than an ethernet hub? All of my prior Internet connections (the ISDN, DSL, and fiber optic) involved a router of one kind or another. In the case of the ISDN and the DSL, I wasn’t in charge of the LAN - I just had an ethernet cable into my space and I plugged that ethernet cable into my computer, or into a hub if I was connecting more than one. With the fiber optic connection, it was basically the fiber running into the house and then into a router, and then my computer (and those of my roomates) were connected directly into the router. When I wanted to connect a second computer in my own room, I just added a hub, which worked fine.

So if a router is what I need here, that’s no problem. I just don’t want to buy a router if it won’t solve my problem.

2

You say “ethernet hub”. What is this “hub”? Make and model please.

You either have an ethernet switch or a router. If the former, then you need some way to assign IP addresses to your computers. You may do this statically by manually specifying the IP addresses each machine is to use, or you may do it dynamically using DHCP.

If you are running a router, it will handle the DHCP for you. If you have a switch, either you have to run DHCP on one of the machines (probably the mac) or you have to use static IPs.

Also, on the mac, you have to run samba in order to be able to talk via SMB with Windows.

Beyond that, and this matters to Windows particularly, you will have to place both the Mac and Windows into the same workgroup.

Once you’ve taken care of all these things, it should work without further trouble.

edit: your modem will handle the DHCP for one connection. However, it might only allow one machine to connect, hence if you are using an ethernet switch it won’t work with you.

3

If your hub is really hub, and not a router, then this isn’t going to work. Your cable provider will give out one IP to the first thing that asks for it, and the hub shares that Ethernet segment with everything that’s attached to it. If it’s a switch, you’ll still have all the devices on the same IP network, but different Ethernet segments.

A router will isolate your computers on their own private network, and forward traffic from them to the Internet. The router takes the one IP address that your cable provider gives you and hands out private addresses to your computers.

So, to sum up:

Hub: Bad. (I don’t even think they even make Ethernet hubs any more.)
Switch: Not what you need
Router: What you need.

4

This isn’t going to work if the switch does not have facilities for creating an isolated network. (Or unless you buy additional public IPs from the cable provider.)

The traditional definition of “switch” does not include these capabilities, but there are some models sold under terms like “managed switch” that provide some smartness without all the capabilities of a proper router. Things can get blurry.

5

He might literally have a hub, which would be the problem here-- nothing’s actually doing any switching or routing.

6

Okay, yeah, it’s a 5-port Netgear “10/100 Mbps Ethernet Switch”. Model FS605 v.3

FWIW, I’m not interested in the two machines talking to each other (no need); I just want to be able to connect both to the Internet at the same time. The Mac is my “working” machine; the Windows laptop is to be just a “side utility” machine, with the primary purpose being to allow me to log two accounts into the same online game at the same time.

That’s pretty much what I suspected. So it could assign its “single connection/IP address” to a router, and then the router would handle assigning IPs to however many computers I attach to it?

7

Yup.

The alternative is to get a second network card/USB network adaptor and turn one of your two computers into a router, but I wouldn’t recommend that for several reasons. One of which is, it’s not easy. And another is, you’d have to keep that computer turned on and plugged in all the time, and it sounds like you have laptops.

The good news is you can find routers cheap, and get wifi out of the deal while you’re at it.

8

One iMac, one laptop, and yeah, I’m not gonna try opening either one :stuck_out_tongue:

I guess I’ll be buying a router then. It’s nice living a 3-minute walk from Radio Shack.

Thanks for the advice, all!

9

A’ight, I’m all set up with a new Belkin wireless router, and everything appears to be working fine. Thanks again :slight_smile:

10

That’s pretty much what I suspected. So it could assign its “single connection/IP address” to a router, and then the router would handle assigning IPs to however many computers I attach to it?

Yup, that’s it.

The presence of the router also provides you with a nice layer of security against drive-by attacks.