WINDOWS 1002000 PROFESSIONAL RESOURCE KIT [Electronic resources] نسخه متنی

Troubleshooting

The following sections describe the common problems with Network and Dial-up Connections and the troubleshooting tools provided with Windows 2000.

Troubleshooting Tools

There are many tools within Windows 2000 that allow you to monitor and diagnose network and dial-up connections. PPP logging records the series of programming functions and PPP control messages during a PPP connection. You can verify whether your modem is working properly by using modem diagnostics and logging. The Netdiag tool can be used to test many networking components. It can be configured to run and report on tools such as Ping, IPConfig, and so on.

PPP Logging

You can troubleshoot Windows 2000 Professional PPP client connections by using PPP logging on Windows 2000. PPP logging records the series of programming functions and PPP control messages during a PPP connection and is a valuable source of troubleshooting information when you are troubleshooting the failure of a PPP connection. To enable PPP logging on your Windows 2000 remote access server, select the Enable Point-to-Point Protocol (PPP) logging option on the Event Logging tab from the properties of a remote access server using the Routing and Remote Access administrative tool.

To enable PPP logging on the client that is initiating the connection, use the Netsh command. The syntax for the command is:

Netsh ras set tracing ppp enabled

Conversely, if you want to stop PPP logging, the command syntax is:

Netsh ras set tracing ppp disabled

Modem Logging

By using Phone and Modem Options in Control Panel, you can record a log of commands as they are sent to your modem by communication programs or the operating system. On Windows 2000 Professional, logging is always turned on and the log is overwritten at the beginning of every session unless you select the Append to Log check box.

NOTE

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Commands sent to the modem are captured in the file %SystemRoot%ModemLog_Model.txt. %SystemRoot%is usually C:WinntSystem32. Model is the name of the modem as it appears in the list of installed modems on the Modems tab of Phone and Modem Options.

Modem Diagnostics

You can verify whether your modem is working properly by using the diagnostics that are available by means of Phone and Modem Options in Control Panel.

When you query a modem, Windows 2000 runs the commands and displays the results, as shown in Table 21.7.

Table 21.7 Modem Query Commands and Responses

NetDiag

The Netdiag tool is available in the support tools directory of your Windows 2000 Professional operating system CD. Netdiag isolates networking and connectivity problems by performing a series of tests to determine the state of your network client and its functionality. Optionally, it can generate a report of the results. For example, it can report on the network adapter configuration details, including the adapter name, configuration, media, globally unique identifier (GUID), and statistics. Using it, you can run a comprehensive sequence of networking tools such as Ping, IPConfig, and so on. For more information about Netdiag, see "Troubleshooting Tools and Strategies" in this book.

Device Manager

Device Manager provides you with information about how the hardware on your computer is installed and configured. It can help you determine the source of resource conflicts, and the status of COM ports. You can also use Device Manager to check the status of your hardware and update device drivers, such as modem drivers, on your computer.

Troubleshooting Configuration Problems

The following sections describe common problems that you might encounter, and possible causes and solutions for them.

The modem does not work.

The modem is incompatible. If you have access to another computer with an Internet connection, check the list of compatible modems in the Hardware Compatibility List link on the Web Resources page at http://windows.microsoft.com/windows2000/reskit/webresources.

The modem is not connected properly or is turned off. Verify that the modem is connected properly to the correct port on your computer. If the modem is external, verify that the power is on.

The remote access server is not running. Ask your system administrator to verify that the remote access server is running. If the server is down, the administrator needs to check the error and audit logs to see why the service stopped. After the problem is fixed, restart the service. If the service is running, the administrator needs to check whether other remote access clients can connect properly. If other clients can connect, the problem might be specific to your workstation.

You do not have a valid user account, or you do not have remote access permission. Verify with your system administrator whether your user account has been established, and that you have remote access permission.

You dialed the wrong number, or you dialed the correct number but forgot to dial an external line-access number, such as 9. Verify that the number is correct as dialed.

Your modem cannot negotiate with the modem of the server. Try using the same type of modem as the server.

The modem cabling is faulty. Do not use the 9-to-25-pin converters that are included with most mouse hardware because some of them do not carry modem signals. To be safe, use a converter made especially for this purpose.

The telephone line (for example, in your hotel room) does not accommodate your modem speed. Select a lower bits-per-second (bps) rate (or call the hotel manager to request a direct line).

The line you are trying to use is digital. Most modems work only with analog phone lines. Verify that you have analog phone lines installed or, if you have digital phone lines installed, verify that the servers and clients have digital modems.

When trying to connect, a message is received that says the remote access server is not responding.

At higher bits-per-second (bps) rates, your modem is incompatible with the modem of the server.

There is a lot of static on the phone line, which prevents a modem from connecting at a higher bps rate.

There is some kind of switching equipment between the client and server that prevents the two modems from negotiating at a higher bps rate. Adjust the speed of your modem to a lower bits-per-second (bps) rate.

The remote access server is not running. Ask your system administrator to verify that the server is running. The modem always connect at a lower bit-per-second (bps) rate than specified.

The modem and telephone line are not operating correctly. Excessive static on the telephone line causes sessions to be dropped. You can use modem diagnostics to confirm correct modem operation.

The destination server is not running properly. Ask your system administrator to verify that the destination server is running properly. Try connecting to the same server from another workstation. If other workstations are having the same problem, there might be problems with server applications or hardware. If not, the problem is specific to your workstation.

The quality of your line is insufficient. Contact your telephone company to verify the quality of your line.

The line you are dialing is affecting the speed. If you can connect to your remote access server by using more than one number, try another number and see if the speed improves.

Your modem software needs to be updated. Check with your modem manufacturer for modem software updates.

The sessions with a remote access server on the network keep getting dropped.

Call waiting is disrupting your connection. Verify that the phone has call waiting. If so, disable call waiting and try calling again.

The remote access server disconnected you because of inactivity. Try calling again.

Someone picked up the phone. Picking up the phone automatically disconnects you. Try calling again.

Your modem cable is disconnected. Verify that the modem cable is connected properly.

Your modem software needs to be updated. Check with your modem manufacturer for modem software updates.

Your modem settings need to be changed because of a remote access server change. Verify the modem settings with your system administrator.

Connections are disconnecting abnormally.

The remote access server is not running. Ask your system administrator to verify that the server is running.

Your modem is unable to negotiate correctly with the modem of the remote access server. The serial port of the computer cannot keep up with the speed you have selected. Try to connect at a lower initial port speed.

Your modem software needs to be updated. Check with your modem manufacturer for modem software updates.

When trying to connect, a hardware error is received.

The modem is turned off. Verify that the modem is turned on. If the modem is turned off, turn it on and redial.

Your modem is not functioning properly. Enable modem logging to test the connection.

Your cable is incompatible. If your modem communicates through Terminal, but not through Network and Dial-up Connections, the cable that attaches your modem to the computer is probably incompatible. You need to install a compatible cable.

Connections do not appear in the Network and Dial-up Connections folder.

The folder might need to be refreshed. Press F5 to refresh the folder.

Conflicts between serial ports are causing connection problems.

The serial ports are conflicting. COM1 and COM3 share interrupt request (IRQ) 4. COM2 and COM4 share IRQ 3. As a result, for serial communications, you cannot use COM1 and COM3 simultaneously, or COM2 and COM4 simultaneously. For example, you cannot use Network and Dial-up Connections on COM1 and Terminal on COM3.

This rule applies if you are using the mouse in addition to other serial communications programs such as Network and Dial-up Connections or the Windows 2000 Terminal program. The rule does not apply if you are using an intelligent serial adapter such as a DigiBoard serial card.

When trying to connect by using ISDN, a "No Answer" message is received.

The remote access server did not answer because it is turned off or the modem is not connected. Contact your system administrator.

The line is busy. Try calling later, or contact your system administrator.

There is a problem with the hardware. Verify that the ISDN adapters are installed and configured correctly.

Your phone number is not configured correctly. In some cases, each B channel on an ISDN line has its own number, while in other cases both B channels share a single number. Your telephone company can tell you how many numbers your ISDN line has.

If you are located in the United States or Canada, your Service Profile Identifier (SPID) is configured incorrectly. The SPID normally consists of the phone number with additional digits added to the beginning, the end, or both. The SPID helps the switch understand what type of equipment is attached to the line and routes calls to appropriate devices on the line. If an ISDN channel requires a SPID, but it is not entered correctly, then the device cannot place or accept calls. Verify that the SPID is entered correctly.

A poor line condition (for example, too much static) interrupted your connection. Wait a few minutes and try dialing again.

You did not enable line-type negotiation, or a connection cannot be made with the line type you selected. Enable line-type negotiation.

Your ISDN switching facility is busy. Try again later.

Your DigiBoard card is too old. If you do not have the latest PCIMAC-ISA DigiBoard card, serial number A14308 or greater, contact DigiBoard for a replacement.

Connections made by using X.25 fail.

The dial-up PAD is configured with the wrong X.3 parameters or serial settings. If the remote access server is running and you cannot connect to it directly through an X.25 smart card or an external PAD, modify the dial-up PAD X.3 parameters or serial settings. Ask your system administrator for the correct settings.

New Pad.inf entries are incorrect. You can check other Pad.inf entries for direct connections and external PADs, and view the comments that go with them. You might need a line analyzer or a terminal program to see the response for the PAD. For dial-up PAD entries, you can use an entry in Pad.inf as an example, paying attention to the comments that go with the example.

Your modem is incompatible. If the modem that connects to a dial-up PAD connects at a lower speed than it should, replace the modem with a compatible one.

The line for the remote access server is congested. If a connection has been established, but the network drives are disconnecting, and you are dropping sessions or getting network errors, the cause might be congestion on the leased line for the remote access server.

For example, four clients connecting at 9,600 bps (through dial-up PADs) require a 38,400-bps (four times 9,600) leased line on the server end. If the leased line does not have adequate bandwidth, it can cause time-outs and degrade performance for connected clients. This example assumes that Routing and Remote Access is using all the bandwidth. If Routing and Remote Access is sharing the bandwidth, fewer connections can be made.

Your system administrator needs to verify that the speed of the leased line can support all the COM ports at all speeds clients use to dial in.

Connections through PPTP fail.

TCP/IP connectivity problems are keeping you from connecting to the PPTP server. You or your system administrator can use the ipconfig and ping commands to verify a connection to your server.

A Winsock Proxy client is active. A VPN connection cannot operate with an active Winsock Proxy client. Winsock Proxy immediately redirects packets to the proxy server before they can be processed by a virtual private network connection for encapsulation. Ask your system administrator to disable the Winsock Proxy client.

You do not have the appropriate connection and domain permissions on the remote access server. Contact your system administrator.

If you are using the TCP/IP protocol, you do not have a unique TCP/IP address. Contact your system administrator.

Name resolution problems are keeping you from resolving names to IP addresses. Specify fully qualified domain names and IP addresses in your connection.

Connections made by using PPP or TCP/IP utilities are failing.

The server does not support LCP extensions. If you cannot connect to a server by using PPP, or the remote computer terminates your connection, the server might not support LCP extensions. In Network and Dial-up Connections, clear the Enable LCP extensions check box.

IP header compression is keeping TCP/IP tools from running. If you successfully connect to a remote server by using PPP, but TCP/IP tools do not work, the problem might be IP header compression. Try to reconnect after turning off IP header compression.

Connections made by using Internet Connection Sharing are failing.

The wrong LAN network adapter is shared. A computer with Internet Connection Sharing needs two connections. One connection, typically a LAN adapter, connects to the computers on the home network and the other connection connects the home network to the Internet. You need to ensure that Internet Connection Sharing is enabled on the connection that connects your home network to the Internet.

TCP/IP is not installed on home network computers. By default, the TCP/IP protocol is installed on computers running Windows 2000, Windows 98, and Windows NT 4.0. If users on your home network are running operating systems other than these, verify that TCP/IP is installed on their computers.

If users on your home network cannot reach the Internet, TCP/IP is incorrectly configured on their home network computers. Verify that the following TCP/IP settings are established on home network local area connections:




IP address: Obtain an IP address automatically (through DHCP).

DNS server: Obtain DNS server address automatically.

Default gateways: None specified.




For computers running Windows 95, Windows 98, or Windows NT 4.0, you can find the TCP/IP settings in Network Control Panel.

If users on your home network cannot reach the Internet, their Internet options need to be modified. Home network user Internet options must be modified for use on the local area network. For more information, see Windows 2000 Help.

The Internet Connection Sharing service is not started. Use Event Viewer to verify that the Internet Connection Sharing service is started.

The Internet Connection Sharing computer is not properly configured for name resolution. You might need to configure the DNS name resolution services on the computer. If computers on the branch office network cannot resolve names to IP addresses, you can check the name resolution configuration of the Internet Connection Sharing computer by using the ipconfig command.

There are two ways that your ISP can configure name resolution:




Statically assigned name servers

If you have statically assigned name servers, you can use the ipconfig command at any time to get the IP addresses of your configured name servers.

Dynamically assigned name servers

The IP addresses of the name servers provided by the ISP are dynamically assigned whenever you dial the ISP. If you have dynamically assigned name servers, you must run the ipconfig command after a connection to the ISP has been made.




If you cannot play a game across the Internet, the protocol used by the application is not translatable. Try running the application from the ICS computer. If the application works from the ICS computer but not from a computer on the home network, then the application might not be translatable.

If you cannot play a game across the Internet, the application is not configured on the computer running Internet Connection Sharing. Verify that the application, including port numbers, is configured correctly.

For more information, see Windows 2000 Help.

If Internet users cannot see services on your home network, such as a Web server, the service is not configured correctly. Verify that the service, including port numbers and TCP/IP addresses, is configured correctly.

If users on your home network cannot reach the Internet sites by using friendly names, there is a DNS resolution problem. Users on your home network must use fully qualified domain names or IP addresses when accessing Internet resources.

When using a local area network connection, there is no response.

There might be problems with your network adapter. Check the appearance of the local area connection icon. Depending on the status of the local area connection, the icon appears in different ways in the Network and Dial-up Connections folder. Also, if the local area connection media is disconnected (for example, the cable is unplugged), a status icon is displayed in the taskbar. Also, use Device Manager to verify that your network adapter is working correctly.

The LAN cable might not be plugged into the network adapter. Check to make sure the LAN cable is inserted into the network adapter. When using a laptop to connect to an ISP, some or all of the applications do not run properly.

The Winsock Proxy client might be preventing your applications from running properly when you use the ISP connection. If you are a mobile user and use your portable computer in your corporate environment, you might need to disable the Microsoft Winsock Proxy client (WSP Client in Control Panel) when you use the same computer to dial to an ISP or other network. For example, if you use a portable computer in your office and use the same computer to connect to an ISP or other network from your home, you might have problems running all of your applications when you use the ISP connection. (For example, your applications might not be able to find the resources or servers they need.) If this is the case, disable the Microsoft Winsock Proxy client (WSP Client in Control Panel) to run the applications that you typically run when you use your portable computer in the corporate office.

I can connect to my ISP, but I cannot browse the Internet.

DNS options might need to be configured. Check with your ISP or your system administrator to see if you need to configure DNS settings in the TCP/IP settings for their connection. For example, you might need to specify a preferred or alternate DNS server address, rather than letting the DNS server address be obtained automatically.

Incoming connection clients cannot see resources beyond the incoming connection computer.

If the addresses that are being allocated to incoming clients are not a subset of the network to which the incoming connection computer is attached, you must create a route to the incoming clients on the intranet computers.

Reconfigure your range of IP addresses that are being allocated to incoming clients so that it is a subset of the network to which the incoming connections computer is attached. If you cannot do this, then configure your intranet hosts with the IP address of the incoming connection computer as a default gateway.

If your intranet hosts are configured to obtain an IP address automatically and a DHCP server is present, you can configure your DHCP server to assign the default gateway.

If your intranet hosts are configured to obtain an IP address automatically and a DHCP server is not present (you are using the Automatic Private IP Addressing feature of Windows 2000 and Windows 98), then you must manually configure all of your intranet hosts with an IP address, subnet mask, and default gateway.

The calculated range of addresses allocated to connecting clients is larger than the range that you configured. Most TCP/IP networks use subnets to effectively manage routed IP addresses. For the range that you specified in From and To, Windows 2000 calculates the closest matching subnet. The range of addresses in the closest matching subnet might exceed the range that you specified. Unless the addresses specified in From and To are subnet boundaries, the range based on the calculated subnet is larger than the range that you specified. To avoid this, specify a range that falls on subnet boundaries. For example, if you are using the 10.0.0.0 private network ID for your intranet, a range that falls on subnet boundaries is 10.0.1.168 to 10.0.1.175. Or, if you are using the 192.168.0.0 private network ID for your intranet, a range that falls on subnet boundaries is 192.168.1.0 to 192.168.1.255.