Troubleshooting your network connection

Connection problems

  1. My laptop has both an Ethernet adapter and a wireless adapter, but I cannot connect to the Internet.
  2. I can use my Web browser to connect to the University's home page, the Library, and other on-campus sites, but I can't connect to Web sites outside the University.
  3. My computer worked at home using a dial-in connection. Now that I'm using an on-campus Ethernet connection, whenever I start Internet Explorer my computer tries to dial-in using the modem.
  4. My Ethernet adapter is installed correctly, and I am not receiving any error messages. However, I still cannot connect to the network.
  5. I have a laptop computer. If I don't have my AC adapter plugged in, I cannot connect to the Internet. How can I fix this problem?

Error messages

  1. I received an email message saying my computer is running a DHCP process that is interfering with the network. What should I do?
  2. I can't connect to the Internet. I see an error message about an IP address 169.254.0.0.
  3. When I start my computer, I see the error message: "Error 38. The computer name you specified is already in use on the network."
  4. When I boot up my computer, I see a Windows pop-up balloon with the message: "There is an IP address conflict with another system on the network."
  5. I can ping, but I can't read email or browse the Web using Internet Explorer. I see the error message, "Page can not be displayed."

Wireless adapters

  1. How do I disable/enable my wireless adapter for a Windows 7, Windows Vista, or Windows XP computer?

IP addresses

  1. How do I release/renew the IP address for my computer?
  2. I've registered both my computer's Ethernet adapter and its wireless adapter, but I can't connect to the Internet due to a duplicate IP address error.

Pop-up ads

  1. I see too many pop-up ads when I open my Web browser. And, my computer is so slow!

My laptop has both an Ethernet adapter and a wireless adapter, but I cannot connect to the Internet.

You need to make sure that both your Ethernet adapter and wireless adapter are registered for your computer. You must register each one separately, and you must use only ONE at a time.

To register your computer through your Ethernet adapter, follow these steps:

  1. Disable the wireless adapter.
  2. Connect your computer's Ethernet cable to the Ethernet jack in your residence hall room.
  3. Connect to The Network Page and follow the instructions to log in.
  4. Click Register a computer, iPod or other Internet-enabled device for full Internet access.
  5. Follow the on-screen instructions to register the computer.

To register your computer through your wireless adapter, follow these steps:

  1. Unplug your Ethernet cable from the Ethernet jack in your dorm room.
  2. Enable the wireless adapter.
  3. Check to see if you have a strong wireless signal. When you have a strong wireless signal, connect to UD's Network page and follow the instructions to log in.
  4. Click Register a computer, iPod or other Internet-enabled device for full Internet access.
  5. Follow the on-screen instructions to register the computer.

NOTE

If you have successfully registered both your wireless adapter and your Ethernet adapter, you must use them ONE at a time. If both adapters attempt to connect simultaneouly, you will be unable to connect due to a duplicate IP address error. Make sure that only one of your adapters is enabled at the same time.

NOTE

After you have enabled your wireless adapter, you must turn on your wireless device to connect to the Inernet. You can turn on/off your wireless device in a number of ways. On many laptop computers, a "shortcut" to toggle the wireless device on and off is available. You should check your computer's User's Guide to find this shortcut for your computer. However, in general, these shortcuts are usually one of the following:

  • a key on or near the keyboard that you press (usually the key will have a graphic that represents a wireless network device),
  • a function key combination (on a Dell or Gateway laptop, it is usually the FUNCTION-F2 key combination), or
  • a slider switch.

For example, the following graphic shows a typical slider switch located on the side of a laptop computer. When the wireless connection is enabled, a green light is on.


How do I disable/enable my wireless adapter for a Windows 7, a Windows Vista, or a Windows XP computer?

Windows 7 computer

To disable your wireless adapter follow these steps:

  1. Click Start.
  2. Click Control Panel.
  3. Double-click Network and Sharing Center.
  4. Left-click the Wireless Network Connection icon.
  5. Click Disable.

To enable your wireless adapter follow these steps:

  1. Click Start.
  2. Click Control Panel.
  3. Double-click Network and Sharing Center.
  4. Left-click the Wireless Network Connection icon.
  5. Click Enable.

Windows Vista computer

To disable your wireless adapter follow these steps:

  1. Click Start.
  2. Click Control Panel.
  3. Double-click Network and Sharing Center.
  4. In the left-hand column, click Manage network connections.
  5. Right-click the Wireless Network Connection icon.
  6. Click Disable.

To enable your wireless adapter follow these steps:

  1. Click Start.
  2. Click Control Panel.
  3. Double-click Network and Sharing Center.
  4. In the left-hand column, click Manage network connections.
  5. Right-click the Wireless Network Connection icon.
  6. Click Enable.

Windows XP computer

To disable your wireless adapter follow these steps:

  1. Click Start.
  2. Click Control Panel.
  3. Double-click Network Connections.
  4. Right-click Wireless Network Connection.
  5. Click Disable.

To enable your wireless adapter follow these steps:

  1. Click Start.
  2. Click Control Panel.
  3. Double-click Network Connections.
  4. Right-click Wireless Network Connection.
  5. Click Enable.

How do I release/renew the IP address for my computer?

The steps to release/renew the IP address for your computer depends on the operating system that you use. Instructions for Windows 7, Windows Vista, Windows XP, and Mac OS X are outlined below.

Windows 7 computer

  1. Click Start. Your cursor will appear in the Start Search field.
  2. In the Start Search field, type

  3. cmd

    and then press the key combination SHIFT-CTRL-ENTER.

  4. When you see the User Account Control dialog box, click Continue.
  5. A window with a black background should appear.
  6. In the window, type

  7. ipconfig /release

    Note the space between ipconfig and /release.

  8. Press ENTER.
  9. In the window, type

  10. ipconfig /renew

    Note the space between ipconfig and /renew.

  11. Press ENTER.
  12. The renew command takes longer to execute than the release command. When renewal is complete, the system should respond with an IP address of 10.x.x.x or 128.175.x.x (x is a number).
  13. Log in to The Network Page and register your computer.

Windows Vista computer

  1. Click Start. Your cursor will appear in the Start Search field.
  2. In the Start Search field, type

  3. cmd

    and then press the key combination SHIFT-CTRL-ENTER.

  4. When you see the User Account Control dialog box, click Continue.
  5. A window with a black background should appear.
  6. In the window, type

  7. ipconfig /release

    Note the space between ipconfig and /release.

  8. Press ENTER.
  9. In the window, type

  10. ipconfig /renew

    Note the space between ipconfig and /renew.

  11. Press ENTER.
  12. The renew command takes longer to execute than the release command. When renewal is complete, the system should respond with an IP address of 10.x.x.x or 128.175.x.x (x is a number).
  13. Log in to The Network Page and register your computer.

 Windows XP computer

  1. Click Start.
  2. Click Run.
  3. In the Open field, type

    cmd

  4. Click OK. You should see a window with a black background appear.
  5. In the window, type

    ipconfig /release

    Note the space between ipconfig and /release.

  6. Press ENTER.
    • If the system returns the message, no such command or displays Help text, the command was probably typed incorrectly.
    • If the system returns the message IP configuration and no further information, make sure your Internet Protocol Properties (TCP/IP) are set as:
      • Obtain an IP address automatically, and
      • Obtain DNS server address automatically
    • The system should respond with an IP address of 0.0.0.0 (all zeros).
       
  7. In the window, type

  8. ipconfig /renew

    Note the space between ipconfig and /renew.

  9. Press ENTER.

    • If the system returns the message, no such command or displays Help text, the command was probably typed incorrectly.
    • If the system returns the message IP configuration and no further information, make sure your Internet Protocol Properties (TCP/IP) are set as:
      • Obtain an IP address automatically, and
      • Obtain DNS server address automatically
    • The renew command takes longer to execute than the release command. When renewal is complete, the system should respond with an IP address of 10.x.x.x or 128.175.x.x (x is a number).
  10. Log in to The Network Page and register your computer.

Mac OS X computer (10.5-10.7)

  1. From the Apple menu, choose System Preferences.
  2. Click the Network icon.
  3. From the left-hand column, click on the type of connection you want to renew (e.g., Ethernet or AirPort).
  4. Click the Advanced button in the lower-right corner of the window.
  5. Click the TCP/IP tab at the top of the window.
  6. Click the Renew DHCP Lease button in the upper-right corner of the window.
  7. Click OK.
  8. Log in to The Network Page and register your computer.

I've registered both my computer's Ethernet adapter and its wireless adapter, but I can't connect to the Internet due to a duplicate IP address error.

If you have successfully registered both your wireless adapter and your Ethernet adapter, you must use them ONE at a time. If both adapters attempt to connect simultaneouly, you will be unable to connect due to a duplicate IP address error. If this problem occurs, follow these directions.

I received an email message saying my computer is running a DHCP process that is interfering with the network. What should I do?

If your computer was set up on your home network and configured to allow "Internet Connection Sharing," you must turn that feature off before connecting to UD's network. Consult these step-by-step instructions about how to turn off this feature on Windows computers.

NOTE

If you ever connect the cable of a network-enabled device to your room’s Ethernet wall jack, your Internet connection will be suspended almost immediately because doing so causes interference with our network’s operation.

I can use my Web browser to connect to the University's home page, the Library, and other on-campus sites, but I can't connect to Web sites outside the University.

You need to register your computer using the "UD Network" page, and you must be using your own computer to do so.

  1. Connect to The Network Page using your own computer.
  2. Use your UDelNet ID and password or UD ID and PIN to log in. ONLY use your Social Security number (SSN) and PIN if you have not yet created a UDelNet ID and password.
  3. Click Register a computer , iPod or other Internet-enabled device for full Internet access.
  4. Click on the box to register your computer. After you register your computer, you will need to wait at least 30 minutes for the changes to take effect.
  5. Restart your computer.

I can't connect to the Internet. I see an error message about an IP address that begins with 169.254.0.0.

When a Windows XP computer starts, if no DHCP server can be found, the computer will assign itself an IP address in the Class B range of 169.254.0.0 with a subnet mask of 255.255.0.0. No gateway or DNS server will be assigned. This process is referred to as "Automatic IP Addressing." It is only used in the instance where a Windows XP computer is configured for DHCP and no DHCP server can be located. To determine the problem, try the following:

  1. Check the Ethernet cable—borrow an Ethernet cable that you know works and use it to try to connect.
  2. Improper LAN Connection Proxy setting:
    1. Click Start -> Control Panel -> Internet Options.
    2. Click the Connections tab.
    3. Click LAN Settings at the bottom of the window.
    4. In the Local Area Network (LAN) settings window, uncheck all items currently checked.
    5. Restart the computer.
  3. Check the Ethernet port. Call the IT Support Center at (302) 831-6000 to have an IT technician check if a port is disabled or not operating properly.

I see too many pop-up ads when I open my Web browser. And my computer is so slow!

Spyware is most likely responsible for redirecting or hijacking your browser settings. Follow these instructions for how to prevent and remove spyware.

When I start my computer, I see the error message: "Error 38. The computer name you specified is already in use on the network."

Changing your computer's name usually solves this problem. Follow these steps to change your Windows XP computer's name.

Windows XP computer

  1. Right-click My Computer.
  2. Click Properties.
  3. Click the Computer Name tab.
  4. Click Change.
  5. Change the Computer Name field to your UDelNet ID (i.e., your email username—e.g., jsmith).
  6. Click OK until you are back to your computer's desktop.
  7. Restart your computer.

When I boot up my computer, I see a Windows pop-up balloon with the message: "There is an IP address conflict with another system on the network."

If you are using a laptop with both a built-in Ethernet adapter and a wireless adapter, you should make sure that the wireless adapter is disabled. Your computer and someone else's computer are accidentally using the same IP address.

NOTE

For Windows XP computers, you will not see the IP address. You will need to find it using the following steps:

  1. Click Start.
  2. Click Control Panel.
  3. Double-click Administrative Tools.
  4. Double-click Event Viewer.
  5. Click System Log in the right-side of the window.
  6. Look for an entry under the Source column with the letters TCPIP.
  7. Double-click the entry to access a detailed description of the problem. Write down the IP address of the conflicting network adapter—the IT Support Center will ask for this number.
  8. Call the IT Support Center at 302-831-6000 while you are experiencing this problem. Keep your computer turned on.
    1. Select option 1 from the voice menu.
    2. Press 0.
    3. Please have the following information available for the Support Center staff: Your name, name of your residence hall, room number, phone number, AND the IP address and hardware address from the error message.
    4. Leave your computer on—do not shut it off—until the problem is fixed. A staff member will contact you when the problem has been resolved.

My Ethernet adapter is installed correctly, and I am not receiving any error messages. However, I still cannot connect to the network.

Check the cable and Ethernet wall jack to be sure they work properly. Check to make sure that your Ethernet cable is securely plugged into the Ethernet adapter and into an active Ethernet jack in the wall. The plugs on a 10Base-T Ethernet cable look like larger versions of the plugs on a telephone cable. In many residence hall rooms, the Ethernet jacks have a red label and the phone jacks have a blue label as shown in the graphic below:



In some residence halls on North Campus, both jacks are grey; however, the Ethernet jacks are usually on the right-side as shown in the graphic below:

Most Ethernet jacks also have an icon of a computer, while the phone jacks usually have an icon of a phone. Try moving your Ethernet cable from one Ethernet jack to another. The one to the left is usually the first Ethernet jack activated.

Does your roommate's computer connect to the network?
If so, first try using his or her cable and your wall jack. If that fixes the problem, you have an Ethernet cable that isn't working. If your cable works in your roommate's Ethernet jack, call 302-831-6000 and request that your Ethernet jack be checked.

Check your Ethernet adapter and TCP/IP software.
With the computer running, look at the back of the Ethernet adapter for a green light. If the green light is not on, the adapter may be improperly configured or the wall jack you are trying to use may not be active. If the green light on your Ethernet adapter is on, but you are still unable to connect, call 302-831-8825.

My computer worked at home using a dial-in connection. Now that I'm using an on-campus Ethernet connection, whenever I start Internet Explorer, my computer tries to dial-in using the modem.

When you set up your computer for off-campus modem access to the University's network, Windows assumed that you would always dial in. Follow these steps to configure your Windows system to use the Ethernet adapter when it senses a "live" Ethernet connection.

  1. Click Start.
  2. Double-click Control Panel.
  3. Double-click Internet Options.
  4. Click the Connections tab.
  5. Under Dial-up settings, choose Dial whenever a network connection is not present.
  6. Click OK.

This is a particularly efficient setting for laptop computers: If your computer senses the modem is connected, it will dial in; if it senses that your Ethernet connection is active, it will use that connection.

I can ping, but I can't read email or browse the Web using Internet Explorer. I see the error message, "Page cannot be displayed."

If you see this error message, your computer has a corrupted "winsock registry" entry. Follow these steps to try to fix it. If this procedure doesn't work, call the Support Center at 302-831-6000 to set up an appointment to drop off your computer.

I have a laptop computer. If I don't have my AC adapter plugged in, I cannot connect to the Internet. How can I fix this problem?

If you have this problem, one of the power management settings on your computer is set so that the computer shuts down to save power. On a Windows computer, you can change this setting by following these steps:

  1. Click Start.
  2. Right-click My Computer.
  3. Click Properties.
  4. Click the Hardware tab.
  5. Click Device Manager.
  6. Click the plus sign (+) in front of Network Adapters.
  7. Double-click the name of your Ethernet adapter.
  8. Click the Power Management tab.
  9. Uncheck the Allow the computer to turn off this device to save power option.
  10. Restart your computer.