Setting up a LAN

Many of you may already have done it, and some may already have wanted to set up a LAN (Local Area Network) at home, for a LAN party or elsewhere. This article is once again an attempt to show how easy setting up a LAN can be. Read on to find out more.

Mac to Mac LANs, AppleTalk, FileSharing
There are several ways how multiple Macs can be connected together in a network. The following is a list of the current possibilities, providing a quick "how to".

Serial port LANs
All Macs up to the Beige G3 series come with standard built-in serial ports, also known as LocalTalk ports. Connecting Macs with these ports is as easy as it is slow, the serial ports only support transfer rates of up to 230Kbit/sec, that isn't very much. Some Macs even wimp out at 56Kbit/sec already, these are namely the Performa series and some PowerBooks, including the PowerBook 1400. However, setting up a network via the serial ports can come in very handy to transfer small amounts of data or to play some older or less demanding games.
Setting up two Macs is really easy. All you need to do is hook them together with a printercable, start up Appletalk on both machines, select the correct port in the AppleTalk control panel and there you go. If you want to exchange files or share applications over the network, you will also need to open the FileSharing controlpanel and start filesharing on one or both of the machines, program linking is also activated there. In order to get things going, you'll need to make some things sharing first. To make something sharing, you should select it and then choose "Sharing..." from the file menu or "Get Info" (or cmd-I) and then "Sharing..." in the pull-down menu. You're provided several options, which are upon you to choose or not. After making some sharing items, you might also need to set user name, password etc in the FileSharing controlpanel and create user accounts in the "Users and Groups" controlpanel. To share a disk for example, you will then need to go into the Chooser, select "AppleShare" and click on the network item you want. You will then be prompted to enter your account login and password (that has to be set in the Users and Groups controlpanel of the serving machine).
Setting up multiple Macs is about the same, with the only difference that you will need some more hardware to do so. There are basically two options to connect multiple Macs with LocalTalk: one is to buy a LocalTalk box from your local dealer. Each Mac will need one box, which is then plugged into the serial port. The box itself features 2 ports for regular 4 way telephone cables. To connect them, you just have to form a chain with the cables, terminating the ends with a resistor (that should be supplied). This is very much like a BNC Ethernet network.
The other option is to buy AppleTalk boxes for each Mac, with the sole difference, that these use the more expensive printer cables instead of the phone ones.

These LANs can be used for:

Ethernet LANs
These are a little more complicated from the hardware side, but just as easy in terms of setting them up in Mac OS. There are again various options.

BNC Ethernet requires every Mac to have a BNC port Ethernet card (10Base2 or 10Base5), the Macs are connected via Coax cables, forming a chain, with terminated ends. Setting them up in software is the same as for LocalTalk LANs, with the only difference, that you must select the Ethernet port in the AppleTalk control panel. These networks run between 10 and 20Mbit/sec depending on whether you have 10Base2 or 10Base5 (uncommon). They are nice for gaming, but since no Mac came with BNC standard, it is quite costly. This network is also TCP/IP and Mac IPX capable, this will be explained shortly.

Twisted Pair Ethernet is probably the most common way of connecting computers. Here the possibilities are quite varied.
2 Macs with a Crossover cable: all you need are 2 Macs with an RJ-45 Ethernet port and a crossover twisted pair cable. These can either be bought at your local dealer, made yourself or crossed over with a little adaptor. I wrote about this here. Setting this up is a little more tricky. First of all you have to connect both Macs, then proceed as explained above, choosing Ethernet as the port. When you start a Filesharing connection, some Macs may need you to start Filesharing simultaneously on both machines. That seems to depend on the system version and the hardware. This network can run at either 10Mbit/sec (10BaseT) or 100Mbit/sec (100BaseT/100BaseTX), the Lan will always run on the speed of the slower machine, ie 10BaseT and 100BaseT would give a 10Mbit/sec connection.
Multiple Macs can only be connected using a Hub. A hub is a small box with 4 to 32 Ethernet ports, that are all connected and routed internally. With hubs you can connect 2 to "put in number here" Computers. Hubs can also be connected among themselves, for even more ports. (Stacking or daisychainging). To make a LAN with a hub, you simply have to plug every Mac into a port on the hub, using regular RJ-45 cables and setting up the networks as explained.
There are several kinds of Hubs however. Normal 10BaseT hubs are fairly cheap and you can have them for about 30$ for an 8-port one. Every Mac connected to a 10BaseT hub will run at 10Mbit/sec, even if it has a 10/100BaseT Ethernet card (like all the new G3/G4). A dynamic 10/100BaseT Hub can run 100Mbit/sec if all machines connected support it, otherwise it will run at 10Mbit.
Switched hubs are by far the most expensive, but also the fastest. They route the data in a way that it is only sent to the machine intended, allowing for mixed 10Mbit and 100Mbit transfers. For example Computer A is 100Mbit, Computer B is too, Computer C and D are 10Mbit. A-B will be 100Mbit, A-C, A-D, B-C and B-D will be 10Mbit and C-D will be 10Mbit. These hubs are clearly the nicest, but they cost very much, often exceeding the 1000$ barrier. There are also switches that can be connected to a hub, to enable those switching capabilities.

These LANs can be used for: Of course there is also 1000BaseT, which uses optical or metal wires and run as fast as (a theoretical) 1000Mbit/sec, but since these don't ship as standard equipment with any Mac nor have prices near any competition, I'd stick with 100BaseT for now.

Mixed LANs, TCP/IP and Mac IPX
Now for the most important things: Setting up TCP/IP and IPX networks.

Setting up an IPX LAN should be unproblematic and happen automatically, if an application requires it, but sometimes it does not. In case you run into trouble using Mac IPX, open the Mac IPX control panel and select the interface you want to use (AppleTalk, Ethernet, TokenRing). Appletalk cannot be used in most cases, since it requires an extra gateway software, and TokenRing is a dead standard too.
Mac IPX is set to load itself only when needed, ie when the application starts it up. Sometimes this procedure fails however, so you need to start it manually. You can do so by alt-clicking the interface you want in the control panel. This should take a few seconds and then report "driver loaded" and your IPX address should be shown etc. This may be usefull when playing games in VPC against PCs. These games may require IPX to be activated before VPC launches. Also make sure you have Mac IPX 1.3.1 and nothing older. This protocol is crossplatform and still fairly common in a lot of PC games.

Is clearly most work to do, but many games only run over TCP/IP nowadays. To set it up, go into the TCP/IP control panel and select: For the IP address (, choose something like for the first machine and then start counting up on the last digit: etc.
The highest number allowed is 255. The subnet mask has the be the same on all machines!, what number you choose doesn't matter really though.
For mixed networks you must also set the Windows or Linux machines like that, one IP address for every machine, same subnet mask for the same network.
To start a game, you then have to enter the IP address of the host in the game.
An option for selecting and entering things manually is to set up a server, for example a Windows NT server, preferably with Mac services installed too. The server then has to be set to provide dynamic IP adresses. But since only very few people know how to set up an NT server correctly, and since it also requires an extra Computer, this may be a fairly complicated way of hosting a LAN party.

Other networks
Other networks like IrDA or AirPort don't require any wiring, but have to follow a few other rules, like distance between machines, obstacles, basestations etc. However, setting them up is also fairly easy. All that changes is usually the port chosen in the AppleTalk and/or TCP/IP control panels. There now also is the possibility of connecting Macs via FireWire (instead of a printer cable), or PowerBooks as a drive over FireWire, like it used to be possible to run them in SCSI drive mode. Both these options are not a LAN however, and will therefore not be discussed here either.

Happy gaming, happy sharing!

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© Bensch Blaser, 2000