Troubleshooting Internet Service Provider Login Problems

• Microsoft Windows NT Server version 4.0
• Microsoft Windows NT Workstation version 4.0

SUMMARY

This article describes how to troubleshoot Internet service provider (ISP) logon problems. This article discusses only logon problems, not modem or dialing problems. For information about modem or dialing problems, see the following articles in the Microsoft Knowledge Base:

   ARTICLE-ID: Q161516
   TITLE     : Troubleshooting Modem Problems Under Windows NT 4.0

   ARTICLE-ID: Q162293
   TITLE     : Troubleshooting RAS Client Issues in Windows NT 4.0

MORE INFORMATION

When you attempt to connect to your ISP, you may receive one of the following error messages:

• Error 629: The port was disconnected by the remote machine.
• Error 640: A NetBIOS error has occurred.

• The settings for your dial-up connection to your ISP are configured incorrectly.
• Your ISP's Point-to-Point protocol (PPP) server is not functioning properly.

Verify Your Username and Password

Make sure that Caps Lock is not accidentally on, and then verify that you are typing your username and password exactly as provided by your ISP. If you are not sure what your username and password are, contact your ISP for assistance.

Accept Any Authentication Including Clear Text

Configure your dial-up connection to your ISP to accept any authentication, including clear text. To do so, follow these steps:

1. Click Start, point to Programs, point to Accessories, and then click Dial-Up Networking.

2. Click the phone book entry for your ISP in the Phonebook Entry To Dial box.

3. Click More, and then click Edit Entry And Modem Properties.

4. Click the Security tab, click "Accept any authentication including clear text", and then click OK.

Lower the Connection Speed

If phone line noise or other interference is a problem, lowering your connection speed may allow you to connect to your ISP. To lower your connection speed, follow these steps:

1. Click Start, point to Programs, point to Accessories, and then click Dial-Up Networking.

2. Click the phone book entry for your ISP in the Phonebook Entry To Dial box.

3. Click More, and then click Edit Entry And Modem Properties.

4. Click your modem in the Dial Using box, and then click Configure.

5. In the Initial Speed (BPS) box, click 9600, and then click OK.

6. Click OK.

Disable Hardware Flow Control

Disable Hardware Flow Control in your dial-up connection to your ISP. To do so, follow these steps:

1. Click Start, point to Programs, point to Accessories, and then click Dial-Up Networking.

2. Click the phone book entry for your ISP in the Phonebook Entry To Dial box.

3. Click More, and then click Edit Entry And Modem Properties.

4. Click the Basic tab, click Configure, click the Enable Hardware Flow Control check box to clear it, and then click OK.

5. Click OK.

Disable Modem Error Control

Disable Modem Error Control in your dial-up connection to your ISP. To do so, follow these steps:

1. Click Start, point to Programs, point to Accessories, and then click Dial-Up Networking.

2. Click the phone book entry for your ISP in the Phonebook Entry To Dial box.

3. Click More, and then click Edit Entry And Modem Properties.

4. Click the Basic tab, click Configure, click the Enable Modem Error Control check box to clear it, and then click OK.

5. Click OK.

Disable Modem Compression

Disable Modem Compression in your dial-up connection to your ISP. To do so, follow these steps:

1. Click Start, point to Programs, point to Accessories, and then click Dial-Up Networking.

2. Click the phone book entry for your ISP in the Phonebook Entry To Dial box.

3. Click More, and then click Edit Entry And Modem Properties.

4. Click the Basic tab, click Configure, click the Enable Modem Compression check box to clear it, and then click OK.

5. Click OK.

Disable Software Compression

Disable Software Compression in your dial-up connection to your ISP. To do so, follow these steps:

1. Click Start, point to Programs, point to Accessories, and then click Dial-Up Networking.

2. Click the phone book entry for your ISP in the Phonebook Entry To Dial box.

3. Click More, and then click Edit Entry And Modem Properties.

4. Click the Server tab, click the Enable Software Compression check box to clear it, and then click OK.

Disable LCP Extensions

You may have trouble connecting to your ISP if your ISP's Point-to-Point protocol (PPP) server does not support Link Control Protocol (LCP) extensions. LCP extensions include a Callback option, Time Remaining, and Identification packets as defined in RFC 1570. Contact your ISP to determine whether you should disable LCP extensions.

To disable LCP extension, follow these steps:

1. Click Start, point to Programs, point to Accessories, and then click Dial-Up Networking.

2. Click the phone book entry for your ISP in the Phonebook Entry To Dial box.

3. Click More, and then click Edit Entry And Modem Properties.

4. Click the Server tab, click the Enable PPP LCP Extensions check box to clear it, and then click OK.

Disable IP Header Compression

You may have problems logging on to your ISP if you are using IP header compression (also known as Van Jacobson or VJ header compression). To disable IP header compression, follow these steps:

1. Click Start, point to Programs, point to Accessories, and then click Dial-Up Networking.

2. Click the phone book entry for your ISP in the Phonebook Entry To Dial box.

3. Click More, and then click Edit Entry And Modem Properties.

4. Click the Server tab, and then click TCP/IP Settings.

5. Click the Use IP Header Compression check box to clear it, and then click OK.

6. Click OK.

Connect Using a Terminal Window

Some PPP and SLIP accounts require you to log on using a terminal window, and then type "PPP" or "slip" (without quotation marks) at a terminal prompt to start the session. When you log on, you may also need to prefix your user name with characters such as "P" or "S" or "PPP:" (without quotation marks). Contact your ISP to determine if you must type "ppp" or "slip" at a terminal prompt or if your user name requires a special prefix.

If your ISP requires additional information other than your user name and password, you may need to use a terminal window. To open a terminal window after you connect, follow these steps:

1. Click Start, point to Programs, point to Accessories, and then click Dial-Up Networking.

2. Click the phone book entry for your ISP in the Phonebook Entry To Dial box.

3. Click More, and then click Edit Entry And Modem Properties.

4. Click the Script tab, click Pop Up A Terminal Window, and then click OK.

No Prompt for Username and Password

If you do not receive a prompt for your user name or password when you attempt to connect to your ISP, follow these steps:

1. Click Start, point to Programs, point to Accessories, and then click Dial-Up Networking.

2. Click the phone book entry for your ISP in the Phonebook Entry To Dial box.

3. Click More, and then click Edit Entry And Modem Properties.

4. Click the Security tab, click Unsave Password, and then click OK.

Disable Your Login Script

If you run a login script to connect to your ISP, disable it and try to connect with a pop-up terminal window. If you are able to connect, there may be a problem with your login script file. You may need to contact your ISP for assistance in creating a script file to use with Dial-Up Networking. Windows NT includes several basic script files including:

• Ppp.scp
• Slip.scp
• Cis.scp

If you have a SLIP account, you must use a terminal window or a script file to connect to your ISP. When you are using a SLIP account, most ISPs display your IP address for the session in the terminal window. Most ISPs inform you of your IP address with a message similar to "Your IP address is <###.###.###.###>" or "SLIP session from <###.###.###.###> to <###.###.###.###>." In this case, the second number is usually your IP address. You should enter this in the IP Address box. If the address is the same every time you connect, you can change it in the phone book entry in TCP/IP settings on the Server tab.

Verify the Phone Number

Verify that you are using the correct phone number to connect to your ISP. If you use MSN, The Microsoft Network, as your ISP, verify that you are dialing in to an MSN phone number that supports calls for the service type "Internet and the Microsoft Network."

Mutual Authentication

You may have problems logging in to your ISP if your ISP's PPP server is using mutual authentication. Dial-Up Networking does not support mutual authentication. Contact your ISP to determine whether your ISP's PPP server uses mutual authentication.

PPP Logging

Enabling the PPP logging file (Ppp.log) may help you troubleshoot other problems related to connecting to your ISP's PPP server. For information about how to enable the Ppp.log file, see the following article in the Microsoft Knowledge Base:

   ARTICLE-ID: Q115929
   TITLE     : Enabling PPP Logging in Windows NT

   ARTICLE-ID: Q161426
   TITLE     : How to Enable Logging with Routing and Remote Access