How to network to older mac plus DSL via ethernet hub?

Question

I just got DSL (yeah, probably the last guy on the planet who still had dialup). Anyway, I've been using ethernet to connect my old G3 to my iMac, and had to unplug it to hookup the DSL. I have a five-port ethernet hub that I used for a short time years ago to network my G3 to an even older mac. Can I use this to connect the G3, iMac and DSL? I don't really remember anything about how to use the hub. Can someone give me a little guidance please?

Answer 1

RayDunakin wrote:
I just got DSL (yeah, probably the last guy on the planet who still had dialup). Anyway, I've been using ethernet to connect my old G3 to my iMac, and had to unplug it to hookup the DSL. I have a five-port ethernet hub that I used for a short time years ago to network my G3 to an even older mac. Can I use this to connect the G3, iMac and DSL? I don't really remember anything about how to use the hub. Can someone give me a little guidance please?
You can't use a hub. A hub is an unintelligent system; it repeats all signals it gets down all its ports. This means that if you are connected to the Internet on one port, it will repeat everything on your local network out over the Internet. I'm fairly sure you don't want that.
In addition, a hub does not do NAT, DHCP, or DNS. Basically, it does not assign IP addresses. If you attach devices to a hub, then either they must have fixed IP addresses of their own or something else must assign IPs to them. If you assign your machines fixed IPs in a private network range, because the hub is not a router and does not do NAT (Network Address Translation) and because private networks are just that, private, your machines will not be able to connect to the Internet... but because this is a hub, anything on your network will still go out over the Internet anyway. You won't be able to see the Internet, but anyone on the Internet who wants to and knows how will be able to see you. If you assign your machines fixed IPs in a network range which is not a private network, your network will be visible over the Internet and you will be able to connect... except that you'll be using a visible network range, which probably belongs to someone else, who will object, and when your ISP finds out (which they will in a very short time when the owner of the network range you're using complains to them) you may find that you no longer have an account. Hijacking someone else's network range is a ToS offense for most services. If you don't assign fixed IPs, and rely on DHCP to assign IPs, you will have multiple IPs on your network, all of which are visible over the Internet with no protection whatsoever... and, more important, you're only paying for one IP. Your ISP will be upset. Liberating multiple IPs without paying for them is also a ToS offense.
Connecting via a hub is a very bad idea.
You should get a router. Most home routers have a switch, not a hub, built into them. A router sits between two networks, one your local network, and one the Internet. The router has two IP addresses, one on the Internet (which you're paying your ISP for) and one on your local network (which the ISP doesn't care about). Most home routers can be set to run DHCP (Dynamic Host Configuration Protocol) on the internal network, and set up a network using one of the private ranges. As they are private, they are not routed over the Internet, and whatever you do on the private net stays on the private net, unless you specifically request an Internet connection by running a web browser or an email client or something else that goes out over the Internet. The router will then do NAT for you and send the signal over the Internet, and when it gets a reply, will route it back to your machine. Because the router includes a switch, it will send the reply directly to the machine in question, because a switch is an intelligent device and keeps a list of the machines on the local network and sends the proper signals to the proper machines. (Note that a wireless system is a hub, it broadcasts the signals to everyone in range; there's a reason why I use a wired connection for my systems...) The Internet only sees one IP, that of the router. You can have multiple machines behind the router and neither your ISP nor the rest of the Internet will care.
I have my system set up in the following way:
1 DSL modem talking to the Internet (set in bridge mode, so it's effectively transparent)
2 router talking to the DSL modem (set in NAT and DHCP modes; it controls the network)
3 multiple devices, including an external switch, connected to the router. All are configured to use a private Class C network. I could have up to 254 devices on a Class C network, though that many would probably kill my router which simply isn't built to handle that kind of traffic. My devices include several Macs, several Windows machines, my server, and several printers. You appear to have two or three devices. Your system would work just fine with a standard home router.