Maintaining WINS

from Chapter 18, Microsoft Windows 2000 Administrator's Pocket Consultant by William R. Stanek.

Microsoft Windows Internet Naming Service (WINS) is a name resolution service that resolves computer names to Internet Protocol (IP) addresses. Using WINS, the computer name OMEGA, for example, could be resolved to an IP address that enables computers on a Microsoft network to find one another and transfer information. WINS is needed to support pre-Windows 2000 systems and older applications that use Network Basic Input/Output System (NetBIOS) over Transmission Control Protocol/Internet Protocol (TCP/IP), such as the NET command-line utilities. If you don't have pre-Windows 2000 systems or applications on the network, you don't need to use WINS.

The underlying application programming interface (API) that enables WINS name resolution and information transfers between computers is NetBIOS. The NetBIOS API contains a set of commands that applications can use to access session-layer services. Commonly used extensions for NetBIOS are NetBEUI (NetBIOS Enhanced User Interface) and NBT (NetBIOS over TCP/IP). This chapter focuses on WINS and NBT.

In Microsoft Windows 2000, WINS isn't automatically installed. To install WINS, you'll need to perform the following tasks:

1. Click Start, choose Settings, and then click Control Panel.

2. Double-click the Add/Remove Programs icon.

3. Click Add/Remove Windows Components, and then click Next.

4. Under Components, scroll to and click Networking Services.

5. Click Details.

6. Under Subcomponents of Networking Services, click Windows Internet Naming Service (WINS), and then click OK.

7. If prompted, type the full path to the Windows 2000 distribution files, and then click Continue.

Note: The WINS server should have a static address.

Understanding WINS and NetBIOS Over TCP/IP

WINS works best in client-server environments where WINS clients send queries to WINS servers for name resolution and WINS servers resolve the query and respond. To transmit WINS queries and other information, computers use NetBIOS. NetBIOS provides an API that allows computers on a network to communicate. When you install TCP/IP networking on a Microsoft client or server, NetBIOS over TCP/IP is also installed. NetBIOS over TCP/IP is a session-layer service that enables NetBIOS applications to run over the TCP/IP protocol stack. NetBIOS applications rely on WINS or the local LMHOSTS file to resolve computer names to IP addresses.

On pre-Windows 2000 networks, WINS is the primary name resolution service available. On Windows 2000 networks, Domain Name System (DNS) is the primary name resolution service and WINS has a different role. This new role is to allow pre-Windows 2000 systems to browse lists of resources on the network and to allow Windows 2000 systems to locate NetBIOS resources.

Configuring WINS Clients and Servers

To enable WINS name resolution on a network, you need to configure WINS clients and servers. When you configure WINS clients, you tell the clients the IP addresses of WINS servers on the network. Using the IP address, clients can communicate with WINS servers anywhere on the network, even if the servers are on different subnets. WINS clients can also communicate using a broadcast method in which clients broadcast messages to other computers on the local network segment requesting their IP addresses. Because messages are broadcast, the WINS server isn't used. Any non-WINS clients that support this type of message broadcasting can also use this method to resolve computer names to IP addresses.

When clients communicate with WINS servers, they establish sessions that have three key parts:

• Name registration During name registration, the client gives the server its computer name and its IP address and asks to be added to the WINS database. If the specified computer name and IP address aren't already in use on the network, the WINS server accepts the request and registers the client in the WINS database.

• Name renewal Name registration isn't permanent. Instead, the client has use of the name for a specified period, which is known as a lease. The client is also given a time period within which the lease must be renewed, which is known as the renewalinterval. The client must reregister with the WINS server during the renewal interval.

• Name release If the client can't renew the lease, the name registration is released, allowing the computer name or IP address, or both, to be used by another system on the network. The names are also released when you shut down a WINS client.

Note: Configuring a WINS client is described in the section of Chapter 15 entitled "Configuring WINS Resolution." Configuring a WINS server is described in the section of this chapter entitled "Configuring WINS Servers."

Name Resolution Methods

Once a client establishes a session with a WINS server, the client can request name resolution services. What method is used to resolve computer names to IP addresses depends on how the network is configured. Four name resolution methods are available:

• B-node (broadcast node) Uses broadcast messages to resolve computer names to IP addresses. Computers that need to resolve a name broadcast a message to every host on the local network, requesting the IP address for a computer name.

• P-node (point-to-point node) Uses WINS servers to resolve computer names to IP addresses. As explained earlier, client sessions have three parts: name registration, name renewal, and name release. When a client needs to resolve a computer name to an IP address, the client sends a query message to the server and the server responds with an answer.

• M-node (modified node) Combines b-node and p-node. With it, a WINS client first tries to use b-node for name resolution. If the attempt fails, the client then tries to use p-node. Because b-node is used first, this method has the same problems with network bandwidth usage as b-node.

• H-node (hybrid node) Also combines b-node and p-node. With it, a WINS client first tries to use p-node for point-to-point name resolution. If the attempt fails, the client then tries to use broadcast messages with b-node. Because point-to-point is the primary method, h-node offers the best performance on most networks. H-node is also the default method for WINS name resolution.

If WINS servers are available on the network, Windows clients use the p-node method for name resolution. If no WINS servers are available on the network, Windows 2000 clients use the b-node method for name resolution. Windows computers can also use DNS and the local files LMHOSTS and HOSTS to resolve network names. Working with DNS is covered in the next chapter.

Tip When you use Dynamic Host Configuration Protocol (DHCP) to dynamically assign IP addresses, you should set the name resolution method for DHCP clients. To do this, you need to set DHCP scope options for the 046 WINS/NBT Node Type as specified in the section of Chapter 17 entitled "Setting Scope Options." The best method to use is h-node. You'll get the best performance and have reduced traffic on the network.

Using the WINS Console

When you install a new server, it's configured with default settings. You can view and change these settings at any time using the WINS console.

Getting to Know the WINS Console

To manage WINS servers on a network, you'll use the WINS console. This console is found in the Administrative Tools (Common) folder. The main window for the WINS console is shown in Figure 18-1. As you see, the main window is divided into two panes. The left pane lists the WINS servers in the domain by IP address, as well as the local machine, if it's a WINS server.

Figure 18-1: Use the WINS console to manage WINS server configurations.

By double-clicking an entry in the left pane, you can expand the listing to display the Active Registrations and Replication Partners folders. The Active Registrations folder displays information on the status of registered computer names. The Replication Partners folder shows summary information for WINS servers with which the server replicates registration information.

Adding a WINS Server to the WINS Console

If the WINS console doesn't list the WINS server you want to configure, you can add the server by completing the following steps:

1. Right-click WINS in the console tree, and then select Add Server.

2. Enter the IP address or computer name of the WINS server you want to manage.

3. Click OK. An entry for the WINS server is added to the console tree.

Note: You can also manage local and remote WINS servers through Computer Management. Start Computer Management, and then connect to the server you want to manage. Afterward, expand Services And Applications and then select WINS.

Starting and Stopping a WINS Server

You manage WINS servers through the Windows Internet Naming Service. Like any other service, you can start, stop, pause, and resume WINS in the Services node of Computer Management or from the command line. To manage WINS servers using the Computer Management node, right-click WINS, choose All Tasks, and then select Start, Stop, Pause, Resume, or Restart, as appropriate. You can also manage WINS in the WINS console. Right-click the server you want to manage in the WINS console, choose All Tasks, and then select Start, Stop, Pause, Resume, or Restart, as appropriate.

Viewing Server Statistics

Server statistics provide summary information for WINS that can be helpful in monitoring and troubleshooting WINS. To view server statistics, right-click the server in the WINS console and then select Display Server Statistics. As Figure 18-2 shows, the statistics are displayed in a summary format.

The statistics provide the following information:

• Server Start Time The time that WINS started on the server.

• Database Initialized The time the server's WINS database was initialized.

• Statistics Last Cleared The time the server's statistics were last cleared.

• Last Periodic Replication The time the WINS database was last replicated based on the replication interval set in the Pull Partner Properties dialog box.

• Last Manual Replication The time the WINS database was last replicated by an administrator.

• Last Net Update Replication The time the WINS database was last replicated based on a push notification message that requested propagation.

• Last Address Change Replication The time the WINS database was last replicated based on an address change message.

• Total Queries The total number of queries received by the server since it was last started. Records Found indicates the number of queries successfully resolved. Records Not Found indicates the number of queries that failed.

• Total Releases The total number of messages received that indicate a NetBIOS application has released its name registration and shut itself down.

  

  Figure 18-2: WINS statistics provide information that's useful in monitoring and troubleshooting the service.

  Records Found indicates the number of successful releases. Records Not Found indicates the number of failed releases.

• Unique Registrations The total number of name registration messages received and accepted from WINS clients. Conflicts indicate the number of name conflicts encountered for each unique computer name. Renewals indicate the number of renewals received for each unique computer name.

• Group Registrations The total number of name registration messages received and accepted from groups. Conflicts indicate the number of name conflicts encountered for group names. Renewals indicate the number of renewals received for group names.

• Total Registrations The total number of name registration messages received from WINS clients.

• Last Periodic Scavenging The last time a cleaning took place because of the renewal interval set in the WINS Server Configuration dialog box.

• Last Manual Scavenging The last time a cleaning was initiated by an administrator.

• Last Extinction Scavenging The last time a cleaning took place because of the extinction interval set in the WINS Server Configuration dialog box.

• Last Verification Scavenging The last time a cleaning took place because of the verification interval set in the WINS Server Configuration dialog box.

Configuring WINS Servers

When you install a WINS server, the server is configured with default settings. You can change these settings by completing the following steps:

1. Right-click the server you want to work with in the WINS console, and then select Properties. This displays the dialog box shown in Figure 18-3.

   

   Figure 18-3: Use the Properties dialog box to configure settings for the WINS server.

2. Change property values on the General, Interval, Database Verification, and Advanced tabs as explained in the sections that follow.

3. Click OK when you're finished making changes.

Updating WINS Statistics

The WINS console provides statistics on address registrations and replication. By default, these statistics are updated every 10 minutes. If you want, you can change the update interval or stop automatic updates altogether. To do this, follow these steps:

1. In the WINS console, right-click the server you want to work with, and then select Properties.

2. Click the General tab.

3. To set an update interval, select Automatically Update Statistics Every and then type an update interval in hours, minutes, and seconds.

4. To stop automatic updates, clear the Automatically Update Statistics Every check box. Click OK.

Managing Name Registration, Renewal, and Release

Computer names are registered in the WINS database for a specified amount of time known as a lease. By setting renewal, extinction, and verification intervals, you can control many aspects of the lease.

1. In the WINS console, right-click the server you want to work with, and then select Properties.

2. Access the Interval tab, shown in Figure 18-4, and then use the following fields to configure the WINS server:

   • Renewal Interval Sets the interval during which a WINS client must renew its computer name. It's also known as the lease period. Generally, clients attempt to renew when they reach 50 percent of the lease. The minimum value is 40 minutes. The default value is six days, meaning clients attempt to renew their lease every three days. A computer name that isn't renewed is marked as released.

   • Extinction Interval Sets the interval during which a computer name can be marked as extinct. Once a computer name has been released, the next step is to mark it as extinct. This value must be greater than or equal to the renewal interval or four days, whichever is smaller.

   • Extinction Timeout Sets the interval during which a computer name can be purged from the WINS database. Once a computer name has been marked as extinct, the next step is to purge it from the database. The default value is four days.

     

     Figure 18-4: Configure intervals to customize server operation for your network needs.

   • Verification Interval Sets the interval after which a WINS server must verify old names it doesn't own. If the names aren't active, they can be removed. The minimum value is 24 days. Generally, computer names registered in a different WINS server have a different owner, and thus they fall into this category.

Tip Think of these intervals as giving you a timeline for names listed in the WINS database. Renewal Interval affects when leases are renewed. Extinction Interval affects when names that aren't renewed are marked as extinct. Extinction Timeout affects when extinct names are purged from the database. If you set Renewal Interval to 24 hours, Extinction Interval to 48 hours, and Extinction Timeout to 24 hours, it could take as long as 96 hours for a record to clear out of the WINS database.

Logging WINS Events in the Windows Event Logs

WINS events are logged in the System event log automatically. While you can't turn this feature off, you can turn on detailed logging temporarily to help troubleshoot WINS problems. To turn on detailed logging, follow these steps:

1. In the WINS console, right-click the server you want to work with, and then select Properties.

2. Access the Advanced tab, and then select Log Detailed Events To The Windows Event Logs.

Note: Detailed logging on a busy network can cause a heavy load on the WINS server. Because of this, you should only use detailed logging during testing, troubleshooting, or optimizing.

Setting the Version ID for the WINS Database

The version ID for the WINS database is updated automatically when changes are made to the database. If the WINS database becomes corrupt and you need to restore the database throughout the network, you'll need to access the primary WINS server and then set the version ID to a value higher than the version number counter on all remote partners. Setting a higher version number ensures that the latest information is replicated to replication partners.

You can view and change the current version ID number by completing the following steps:

1. In the WINS console, right-click Active Registrations, and then select Find By Owner. This displays the Find By Owner dialog box.

2. On the Owners tab, the Highest ID column shows the highest version ID number being used on each server. The value is set in hexadecimal format and the maximum value is 2^31.

3. Note the highest version ID value, and then click Cancel.

4. Right-click the entry for the primary WINS server in the console tree, and then select Properties.

5. In the Advanced tab, type a new value in the Starting Version ID field. This value must be entered in hexadecimal format, such as E8B, and should be higher than the value you noted previously. Click OK.

Configuring Burst Handling of Name Registrations

Multiple WINS clients often try to register with a WINS server at the same time. Sometimes this can overload a WINS server, especially if hundreds of computers are all trying to register at the same time. Rather than being unresponsive to new requests, the WINS server can switch to a burst-handling mode. In this mode, the server sends a positive response to client requests before the server processes and enters the requests in the WINS database.

You can modify the threshold for when burst handling occurs to fit the size of your network and the capacity of the server. The default threshold occurs when there are more than 500 registration and name requests in the burst queue. You can set this threshold to a different value by completing the following steps:

1. In the WINS console, right-click the server you want to work with, and then select Properties.

2. In the Advanced tab, make sure that Enable Burst Handling is selected, and then use the following fields to set a new threshold:

   • Low Sets the threshold to 300 registration and name requests.

   • Medium Sets the threshold to 500 registration and name requests. This is the default value.

   • High Sets the threshold to 1000 registration and name requests.

   • Custom Allows you to set a threshold value between 50 and 5000.

3. Click OK when you're finished.

Note: The maximum number of registration and name requests that WINS can handle at any one time is 25,000. The WINS server will drop requests if this limit is exceeded.

Saving and Restoring the WINS Configuration

Once you configure all the necessary WINS settings, you may want to save the WINS configuration so that you can restore it on the WINS server. To save the configuration, type netsh WINS dump >> winsconfig.dmp at the command prompt.

In this example, winsconfig.dmp is the name of the configuration script you want to create. Once you create this script, you can restore the configuration by typing netsh exec winsconfig.dmp at the command prompt.

Tip You can also use this technique to set up another WINS server with the same configuration. Simply copy the configuration script to a folder on the destination computer and then execute it.

from Microsoft Windows 2000 Administrator's Pocket Consultant by William R. Stanek. Copyright © 1999 Microsoft Corporation.

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