After Hours Home LAN instruction kit

This page describes several methods for networking your home or small office LAN to use a shared Internet connection.

You don't need multiple IP addresses from your ISP, or multiple phone lines (but if you have a dialup connection, you might find a dedicated line more convenient than sharing a dialup line with the fax machine or the kids). First, you need to determine what kind of internet connection you have or you want to have. If you already have an Internet Service Provider (ISP), then let's see what you need immediately to connect to the web.

For dialup customers, there are several ways to create a home LAN and share that dialup connection.

Here are the details:

A dedicated router saves you a lot of trouble by making the modem connection available to all computers all of the time regardless of whether other computers are on. The router assigns each computer a unique IP address when it boots up (DHCP), permitting each computer to communicate with all other devices on your network (either by IP or AppleTalk). Routers with dialup modem connections usually require some setup before they are ready to work, using a Web Browser to access the routers settings pages. Often this is as simple as launching a browser from a computer connected to the router and entering in the router's IP address in the URL (e.g., - then supplying the password for access. Once the router is configured with your dialup settings (user id, password, dialup phone number, DNS host addresses and server names, modem initilization information for your brand of modem), the router will take care of activating the modem, dialing up to the ISP, and maintaining the connection as you dictate. Each attached Mac or windows system then has access at the modem speed. The advantage of using a dedicated router is the firewall most have embedded into the device, and models such as the MacSense MIH-108 has 8 ethernet ports built in for network expansion.

If your Mac has an internal modem, you can make that computer the router device by using software such as IPNetRouter. This requires some setup of the software, but combine IPNetRouter with a good ethernet hub or switch and you can use it as a gateway for the rest of your network to the Internet.

For cable or DSL customers, simply use a dedicated router.

Here are the details:

We use a MacSense Xsense Pro router for our home network. This router permits up to four ethernet 10baseT devices to be connected for file sharing and talking to shared printers. The router has another 10baseT port called a WAN port for talking with the cable modem. If the router is configured properly, each computer gets it's own IP address from the router (starting with 192.168) and the router talks to the cable modem as if there is just one computer connected to it. Each computer on the LAN talks through the router to the cable modem for email, web browsing and more. Most routers require just a little bit of setting up to work properly with the cable modem. You might have to program the router with the ISP's DNS settings, but that's generally about it. Because the router manages all of the IP address settings via DHCP (or you can assign static addresses as needed).

If you need to expand your network beyond four devices, simply hook hubs or switches to one of the router ports (be sure to use a crossover cable or uplink port between the router and the expansion hub). Non-ethernet printers can be shared across the network by either using Apple's LocalTalk Bridge control panel (OS 9 or lower, localtalk printers) or USB printer sharing control panel (most USB printers). Other routers such as the Asante or Linksys devices offer similar features and functions. Do be sure to get a router which offers a configurable firewall for added protection. And, yes, you can share this network with Windows PC systems easily, although they may not be able to use all printers the Macs can. DSL customers use the same configurations.

When things go wrong -- some common troubleshooting of home networks and the Internet.

Some ISP services and some models of routers can misbehave, denying you access to the internet across the LAN. Here are some trouble-shooting techniques we use to find the culprit.

Some ISPs are now using special tricks to prevent home LANs from functioning properly. These ISPs claim that home LANs represent a threat to their networks for stability. The truth is that many of these ISPs want to force their users into paying for Internet access for EACH computer which uses their service, rather than just paying for the connection. There is no logical argument to support this billing practice except for raw greed, 'though if an ISP's technical support department were not up-to-speed on router management, they'd be unable to assist home users who may want a LAN - so lack of qualified technical support may also play into an ISPs decision not to support home-based LANs.

While we cannot condone the violation of any written agreement or terms of service (TOS) you may have with your ISP, we can tell you the most common method ISPs use to deny Routers from working properly with their broadband modems: MAC address verification. This MAC address is a special supposedly unique code assigned to any device with an Ethernet connection (and is not an abbreviation for Macintosh). The Ethernet card in your Macintosh or PC, or the one in your network printer, or a router or cable modem will each have a MAC address assigned to it. The ISP will have their equipment record the MAC address of whatever device is the first to successfully use their connection. Any other device (computer or router) with a different MAC address is normally denied service from the modem.
The symptoms of this technique are: one home computer hooked up directly to the cable modem CAN surf the web without issue, but the router (or other computers) cannot get a public IP address from the modem. We need to clone the MAC address from the working computer to the router.

Here's how:

While this is not a comprehensive guide to using routers, LANs or the issues which can occur, hopefully we've given you some good jumping-off points. If you are still having trouble with your system, we'd be happy to provide a site visit to assist in wiring and configuring your LAN. Call us for an appointment.