DSL Troubleshooting


  1. First turn off all equipment, the computer, the router if you have one, and modem/cable box
    and wait a full 10 seconds.

  2. Then turn on the modem/cable box and wait for it to sync. For a modem this means that all the
    applicable lights have come back on and for a cable box when the TV signal is back
    (this could take 5 - 10 minutes). Then the router if you have one, followed by the computer.

  3. Open your browser and check to see if you have a connection, if not then folllow the next steps.

  4. Make sure you have the correct IP information for your network. This would include the:

    • IP Address
    • Subnet Mask
    • Default Gateway
    • DNS Servers
  5. There are a few ways you can see what IP addresses are being assigned. But generally for:

    • Windows 2000/XP - click on "Start" / click on "Run" / type "cmd.exe" in the box / clicl "OK"
    • Windows Vista/7 - click on the Windows Logo / click on "Search / type "cmd.exe" in the box /
      click on "cmd.exe" in the list
    • Type "ipconfig /all" in the black window at the ">_" prompt
    • Here's an example of what you may see:


  6. Check your IP address:

    • If you have a router, common examples would be: 192.168.0.x, 192.168.1.x or 10.0.0.x
    • If you are directly connected to your modem/cable box, you should have the IP address
      from your ISP.
    • What you don't want to have is something like 169.254.x.x. This means you are not getting an
      IP address assigned and this needs to be resolved first.
    • Possible causes for not getting an IP address assigned are:
      • Defective cable, network card or port on the router. Make sure you are using all known
        working components.
      • Your router is not configured for DHCP or does not have the proper settings.

    You need to have this correct before proceeding. If you are behind a router then you should call the
    router manufacturer, if you are connected directly to the modem/cable box call the help desk for
    further assistance.

  7. Also make sure you have the correct subnet mask, this will either be supplied by the router or the
    one from your ISP if you are directly connected.

  8. Make sure you have the correct default gateway, with a router this is typically the IP address of
    your router, if connected directly it is the one from your ISP.

  9. Make sure you have the correct DNS server entries. Sometimes this is the IP address of your router,
    so it would be the same as your default gateway IP. If you are connected directly, it is the actual DNS
    servers used by your ISP.

  10. Try pinging the router's IP address by typing "ping <the router's IP>,"if you get a reply, then your
    connection to the router is working. If you don't get a reply, then you need to double check
    your network card, cable, or the port on the router. You might also see if any other computers
    on the network can do the same. Call the router manufacturer for further assistance.

  11. Try pinging an external site by IP address by typing "ping 66.38.0.16" if you get a
    reply, then you have a connection to the internet. If you don't get a reply, double check that the
    router is connecting to the Internet. Typically you can access the router through your web browser
    and check it's status, call the router manufacturer if you need assistance. If you are directly
    connected to the modem/cable box then call the help desk for further assistance.

  12. Try pinging an external site by name by typing "ping www.google.com", if you get a reply then you
    have a connection to the internet. If you don't get a reply, there are several things you can try:

    • Double check your DNS entries.
    • You many need to use the same DNS IP address that your ISP or router is using.
  13. If you could ping external sites by both IP address and Name, but cannot browse the web, likely your
    web browser is misconfigured. Double check that you don't have an incorrect or not needed proxy
    server assigned.

    • In Internet Explorer: click on "Tools" / click on "Internet Options" / click on the "Connections" tab
      / click on the "LAN Settings" button. / Uncheck both "Automatically detect settings" and "Use a proxy server for your LAN" / click "OK" / click "OK"
    • In Firefox: click on "Tools" / click on "Options" / click on the "Advanced" tab / click on the
      "Network" tab / click on the "Settings" button / select "No Proxy" / click "OK" / click "OK"
  14. If all the above steps fail then call the help desk.