Connecting Your DSL to More than One Mac

As stated in the July 2000 Shop Talk (reprinted from MacOS monthly), there are hundreds of ISPs that offer their DSL service in dozens of ways. There is no single, clear cut way to describe how to connect your DSL to multiple Macs. But, here are a few generic examples of the different ways you could do it based on how some different ISPs work.

Bridging with multiple IP's

This is probably the simplest and easiest to use of them all. When uswest.net first offered DSL service it was this way. They have since converted (and in some cases are still converting) to PPP. In this scheme it is possible to have as many real IP addresses as you have machines. Your CPE just passes them on through from your ISP's DHCP server as your Macs come online. The setup should be this simple:

1. Connect your CPE to the Uplink port on your hub (if the port on the hub is dual mode make sure it is set to Uplink).
2. Connect your Macs to the hub.
3. Make sure that in the TCP/IP Control Panel that it is set as follows:
   1. Connect via Ethernet
   2. Configure using DHCP Server
   3. Enter your ISP's DNS numbers in the Name Server Addr field.
4. Launch your browsers and surf away.

Bridging with one static IP

Here in Portland there is an ISP that works this way. You have a bridged connection but only one static IP is sent down that connection. Consequently, if you want to have multiple machines connected you have to have either a piece of hardware or software that acts as a DHCP/NAT server which will give out non-routable (I like the term "fake") IP's to your computers.

Option A - Hardware

1. Purchase one of the pieces mentioned in the main article.
2. Connect your CPE to the WAN port on your hardware solution.
3. Run a line from the LAN port on your hardware solution to the Uplink port on your hub.
4. Connect your Macs to the hub.
5. Make sure that in the TCP/IP Control Panel that it is set as follows:
   1. Connect via Ethernet
   2. Configure using DHCP Server
   3. Enter your ISP's DNS numbers in the Name Server Addr field.
6. Launch your browsers and surf away.

Option B - Software

1. Purchase one of the pieces mentioned in the mail article and install it on one of your Macs. Configure the TCP/IP on this Mac as specified by the software solution you purchased.
2. Connect your CPE to the Uplink port on your hub (if the port on the hub is dual mode make sure it is set to Uplink).
3. Connect your Macs to the hub.
4. Configure you're the TCP/IP on your Macs as specified by the software solution you purchased.
5. Launch your browser and surf away.

PPP in Routing

Uswest.net is an ISP provides this kind of connection to their DSL customers. Your CPE gets a real IP address and acts as a DHCP/NAT server to the other computers behind it, giving out fake IP addresses. This is also a very simple setup.

1. Connect your CPE to the Uplink port on your hub (if the port on the hub is dual mode make sure it is set to Uplink).
2. Connect your Macs to the hub.
3. Make sure that in the TCP/IP Control Panel that it is set as follows:
   1. Connect via Ethernet
   2. Configure using DHCP Server
   3. Enter your ISP's DNS numbers in the Name Server Addr field.
4. If you have Open Transport version 2.0.3 or 2.5.x you might have to set up your TCP/IP this way:
   1. Connect via ethernet
   2. Configure Manually
   3. Enter your ISP's DNS numbers in the Name Server Addr field.
5. Launch your browsers and surf away.

AirPort

Why should you listen to me ramble on about setting up a Mac network with DSL and Airport when you can read about it directly from Apple?! Download this PDF, follow the instructions and your shouldn't have any worries. I have had some experience with Airport and it really isn't too hard, but we all get stuck at one point or another. If you do, drop me an email and we will see what we can do!

Corby Stephens - corby@macosjournal.com
Corby's Page