Mac OS 9: Troubleshooting a Cable Modem, DSL, or LAN Internet Connection

This document offers a general strategy for troubleshooting cable modem, digital subscriber line (DSL), or LAN connectivity issues.
Symptom

You are not able to connect to the Internet using your cable modem, DSL, or LAN.

Note: If your Internet service provider requires you to connect via PPPoE, stop here and go to technical document 106872, "Mac OS 9: Troubleshooting a PPPoE Internet Connection".


Note: This document does not apply to Mac OS 9 when used in the Classic environment of Mac OS X. The Classic environment uses Mac OS X network settings. For information on Mac OS X connectivity, see technical document 106796, "Mac OS X: Internet and Network Topics (Getting Connected, Troubleshooting)".

Solution

Note: Comments and steps specific to modems do not apply to LAN users. LAN users connect with a hub, connection pod, switch, or router. Cable and DSL users may or may not have these components, depending on the network. LAN users should contact their network administrator instead of an Internet service provider.

Check all cables and power supplies

Verify that all cables related to the modem are plugged in and firmly inserted. This includes the modem's power cord, the cable from the modem to the computer, and the cable from the modem to the wall outlet. To be sure a connection is properly inserted, disconnect and reconnect it. Be sure that cables have not been cut, chewed, or otherwise damaged.

If you have any hubs, pods, or routers in use, be sure to check all cables and power supplies. If you have more than one power supply available for a type of hub or router, try swapping the power supplies. A defective power supply may affect network traffic.

Reset/power cycle modem hardware

Cycle the power on your DSL or cable modem by turning it off for a few minutes then turning it back on. Some ISPs recommend that you unplug the modem's power cord. This is required if the modem does not have a power button. If the modem has a reset button, you may try it before or after cycling the power.

Check indicator lights on modem

Some DSL and cable modems have indicator lights that can provide useful information about cabling connections. A "Cable" light may indicate that the cable network is available, whereas a "PC" light may indicate that the modem recognizes the connection to your computer. If such a light remains off after you have checked your cables and cycled the power, contact your Internet service provider (ISP).

Check TCP/IP Control Panel settings

Open the TCP/IP control panel, and check to be sure that the settings are still correct. If you have an IP address that begins in 169 or 192, then you may not be successfully connecting to the network. For help verifying that your connection is set up properly, see technical document 106867, "Mac OS 9: How to Connect to the Internet via Cable, DSL, or Local Area Network (LAN)".

Network troubleshooting

If you have two or more computers attempting to share an Internet connection, be sure that your network is set up properly. You need to know if your ISP provides only one IP address or if it provides multiple IP addresses. If only one IP address is used, then you must have a router capable of sharing the connection, also known as network address translation (NAT) or "IP masquerading." Check the documentation provided with your router for setup information. Check with the person who set up your network. The AirPort Base Station may be used for this routing function. For more information on using the AirPort Base station, see technical documents:

120061: "Designing AirPort Networks for Mac OS X (v10.1) Manuals"
75138: "Designing AirPort Networks for Mac OS 9 Document"

Contact your ISP

If you have not resolved the issue with the above steps, contact your Internet service provider.
Published Date: Oct 10, 2016