Troubleshooting Microsoft Networking

Tools and techniques are available that can help you identify and resolve problems that you might encounter in a networking environment.

When troubleshooting a network connection in Windows XP Professional, first establish that the following conditions exist:

• The cable connection between the network adapter and the port is secure. If it is, restart the computer in case you have temporarily lost connection.

• The network adapter is correctly installed. Use Device Manager to verify that it is functioning correctly.

• Event Viewer is correctly logging system and application events so that the problem can be fully analyzed. For more information about using Event Viewer and the event logs, see Tools for Troubleshooting later in this chapter.

• At least one domain controllers is available and functioning.

For more information about troubleshooting techniques and tools, see Troubleshooting Concepts and Strategies and Tools for Troubleshooting in this book and Windows XP Professional Help and Support Center.

Tools for Troubleshooting

Windows XP Professional includes tools to help you diagnose and resolve networking problems. For information about the use and syntax of the troubleshooting tools, see Tools for Troubleshooting in this book.

Event Viewer

Event Viewer allows you to monitor events in your system. It maintains logs about program, security, and system events on your computer. You can use Event Viewer to view and manage the event logs, gather information about hardware and software problems, and monitor Windows XP Professional security events. The Event Log service starts by default when you start Windows XP Professional. All users can view application and system logs.

An event log consists of a header, a description of the event (based on the event type), and additional data (optional). A typical log entry consists of the header and a description as shown in Figure 20-6.

Figure 20-6: Typical event log entry

To use Event Viewer to access a security log

1. Right-click My Computer, and then click Manage.

2. Click System Tools, click Event Viewer, and then click Security.

3. In the list of specific security events, double-click the most recent one.

4. In the Event Properties dialog box of the specific security event, read the information about the event and relevant data.

5. Event Viewer categorizes events by log type (for example, security or system) and displays a separate log for every event, which includes date, time, source, category, ID, user account, and computer name.

The log types that directly relate to a user logging on are the security and system logs. Table 20-4 provides a description of the log types and how they can be used in troubleshooting.

Table 20-4: Log Types

Log Type	Description
Security	The Security Log records security events, such as valid and invalid logon attempts, and events related to resource use, such as creating, opening, or deleting files or other objects. For example, the Security log records a user s inability to log on to a domain account due to an incorrect or invalid user ID/password combination.
System	The System Log records events logged by the Windows XP Professional system components. For example, if a driver or other system component fails to load during startup, it is recorded in the System Log. Also, the System Log records a duplicate computer name on the domain as an error message sent by NetBT.

For more information about Event Viewer, see Windows XP Professional Help and Support Center.

Network Connectivity Tester (Netdiag.exe)

This command-line diagnostic tool helps isolate networking and connectivity problems by performing a series of tests to determine the state of your network client and its functionality. Netdiag.exe performs LAN connectivity and domain membership tests, including network adapter status, IP configuration, domain membership, and Kerberos V5 security tests. The tests can be performed as a group or individually.

For more information about the function and syntax of Netdiag.exe, see Tools for Troubleshooting in this book.

Status Menu Command

If your computer is set up to accept incoming connections, an icon with an assigned user name appears in the Network Connections folder as each user connects. You can view the progress of incoming connections by right-clicking a named connection, and then clicking Status.

By using the Status menu command, you can view the following data:

• The duration of a connection.

• The speed at which you initially connected. For a single-link connection and for individual links in a multilink connection, this speed is negotiated (and fixed) at the time the connection or link is established. For multilink connections, this speed is equal to the sum of the speeds of the individual links. For multilink connections, this speed varies as links are added or deleted.

• For local area connections, the number of bytes transmitted and received during a connection. For other types of connections, the number of bytes transmitted and received during a connection, and the associated compression and error statistics.

• The diagnostic tools that you can use for a connection, if any. For example, the Windows Network Troubleshooter, TCP/IP Autoping, and TCP/IP Windows IP Configuration.

The Support tab in the Local Area Connection Status Dialog box

The Support tab in the Local Area Connection Status dialog box allows you to do the following:

• View the address type, IP address, subnet mask, and default address of a connection.

Use the Details button to view a detailed summary of the network connection, which includes its physical address, the IP address of its DHCP, DNS and WINS servers, the date the DHCP lease of the address was obtained, and the date the DHCP lease is due to expire. This is in addition to the IP address, subnet mask, and default address of the connection.

• Open the Network Diagnostics page of Windows XP Professional Help and Support Center.

• Repair your settings by pressing the Repair button. This does the following:

  • Releases current TCP/IP settings.

  • Renews your TCP/IP settings.

  • Registers the DNS resource records for all adapters on your Windows XP Professional based computer. All errors are reported in the Event Viewer within 15 minutes of the time registration is initiated. On the command line, you can achieve similar results by using ipconfig/registerdns .

  • Flushes the ARP cache

  • Does a DHCP broadcast renew for the IP lease.

  • Purges and reloads the remote cache name table of NetBT. On the command line, you can achieve similar results by using Nbtstat -R .

  • Sends Name Release packets to WINS and then starts refresh. On the command line, you can achieve similar results by using Nbtstat -RR .

  • Purges the dns resolver cache and re-registers the DNS recodes. On the command line, you can achieve similar results by using ipconfig/flushdns .