Microsoft Windows Internet Name 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 NetBIOS Enhanced User Interface (NetBEUI) and NetBIOS over TCP/IP (NBT). This chapter focuses on WINS and NBT.
In Windows Server 2003, WINS isn’t automatically installed. To install WINS, you’ll need to perform the following tasks:
Click Start, choose Programs or All Programs, Administrative Tools, and then select Configure Your Server Wizard.
Click Next, and then click Next again. The current server roles are shown.
Select WINS Server from the Server Role list box, and then click Next.
Click Next. The wizard installs WINS and begins configuring the server. As necessary, insert the Windows Server 2003 CD when prompted.
Click Finish and then close the Manage Your Server console.
From now on, the WINS service should start automatically each time you reboot the server. If it doesn’t start, you’ll need to start it manually. See the section of this chapter entitled "Starting and Stopping a WINS Server."
Note
WINS servers should have static IP addresses. This ensures that WINS clients can consistently connect to the server.
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, NBT is also installed. NBT 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 and Windows Server 2003 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, Windows XP, and Windows Server 2003 systems to locate NetBIOS resources.
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 renewal interval. 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 another system on the network to use the computer name or IP address, or both. The names are also released when you shut down a WINS client.
Note
Configuring a WINS client is described in the section entitled "Configuring WINS Resolution" in Chapter 16. Configuring a WINS server is described later in this chapter in the section entitled "Configuring WINS Servers."
After a client establishes a session with a WINS server, the client can request name resolution services. Which 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). 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. On a large network with hundreds or thousands of computers, these broadcast messages can use up valuable network bandwidth.
P-node (peer-to-peer). 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. In this mode, 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 (mixed). 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). Also combines b-node and p-node. With it, a WINS client first tries to use p-node for peer-to-peer name resolution. If the attempt fails, the client then tries to use broadcast messages with b-node. Because peer-to-peer 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 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, "Chapter 20."
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 entitled "Setting Scope Options" in Chapter 18. The best method to use is h-node. You’ll get the best performance and have reduced traffic on the network.
When you install a new WINS server, it’s configured with default settings. You can view and change these settings at any time using the WINS console.
To manage WINS servers on a network, you’ll use the WINS console. This console is found in the Administrative Tools folder. The main window for the WINS console is shown in Figure 19-1. 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.
By double-clicking a server 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 about the status of registered computer names. The Replication Partners folder shows summary information for WINS servers, with which the server replicates registration information.
If the WINS console doesn’t list the WINS server you want to configure, you can add the server by completing the following steps:
You manage WINS servers using Windows Internet Name Service (WINS). Like any other service, you can start, stop, pause, and resume WINS in the Services node of Computer Management as well as from the command line. To manage WINS servers using the Services node of Computer Management, 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.
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. The statistics are displayed in a summary format and 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 an administrator last replicated the WINS database.
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 that a NetBIOS application has released its name registration and shut itself down. 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 an administrator initiated a cleaning.
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.
WINS Partner. The number of successful replications with WINS partners as well as the number of failed communications with WINS partners.
When you install a WINS server, the server is configured with default settings. You can change these settings by completing the following steps:
Right-click the server with which you want to work in the WINS console and then select Properties. This displays the dialog box shown in Figure 19-2.
Change property values in the General, Intervals, Database Verification, and Advanced tabs as explained in the sections that follow. Click OK when you’re finished making changes.
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:
In the WINS console, right-click the server with which you want to work and then select Properties.
If necessary, click the General tab.
To set an update interval, select the Automatically Update Statistics Every check box and then type an update interval in hours, minutes, and seconds. Click OK.
To stop automatic updates, clear the Automatically Update Statistics Every check box. Click OK.
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.
In the WINS console, right-click the server with which you want to work and then select Properties.
Click the Intervals tab shown in Figure 19-3 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, which means that 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.
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.
Figure 19-3. In the Intervals tab, configure intervals to customize server operation for your network needs.
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.
WINS events are logged in the System event log automatically. Although you can’t turn this feature off, you can temporarily turn on detailed logging to help troubleshoot WINS problems. To turn on detailed logging, follow these steps:
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:
In the WINS console, expand the node for the server with which you want to work. Right-click Active Registrations and then select Display Records.
In the Record Owners tab, the Highest ID column shows the highest version ID number being used on each server.
Tip
The value shown is in decimal format. However, you set version ID in hexadecimal format, and the maximum value is 2^31. To convert the decimal value to hexadecimal value, you can use the Calculator. Start Calculator from Accessories. Select Scientific from the View menu. Click the Dec button (which stands for Decimal) and then type the ID value. Click the Hex button (which stands for Hexadecimal) and the previously entered value is automatically converted to Hexadecimal. Note the value.
Note the highest version ID value and then click Cancel.
Right-click the entry for the primary WINS server in the console tree and then select Properties.
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.
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 at which burst handling occurs to fit your network’s size and the server’s capacity. The default threshold occurs when more than 500 registration and name requests are in the burst queue. You can set this threshold to a different value by completing the following steps:
In the WINS console, right-click the server with which you want to work and then select Properties.
In the Advanced tab, make sure that the Enable Burst Handling check box 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.
Click OK when you’re finished.
After you configure all the necessary WINS settings, you might want to save the WINS configuration so that you can restore it on the WINS server. To save the configuration, type netsh dump WINS > winsconfig.dmp at the command prompt.
In this example, winsconfig.dmp is the name of the configuration script you want to create. After you create this script, you can restore the configuration by typing netsh exec winsconfig.dmp at the command prompt.
You can configure WINS servers to replicate their databases with one another. This ensures that each server’s database is current and reflects changes on the network. As an administrator, you have many options for controlling when replication occurs. You can also force replication at any time.
Replication is handled with push partners and pull partners. A push partner is a WINS server that notifies other WINS servers of changes on the network. A pull partner is a WINS server that requests replicas from a push partner. You can configure any WINS server as a push partner or pull partner, or both.
To increase the reliability of replication, you can configure persistent connections between replication partners. With persistent connections, replication partners keep connections open even when they’re idle. This allows the WINS servers to replicate changes throughout the network quickly and efficiently.
Before you create replication partners, you’ll want to set default parameters. These parameters are used to configure new push and pull partners.
General parameters control replication and migration. You can set general parameters by completing the following steps:
Expand the view for the server with which you want to work in the WINS console.
Right-click Replication Partners in the tree view and then choose Properties.
In the General tab, select or clear the Replicate Only With Partners check box. If it’s selected, this option ensures that WINS information is replicated only with designated replication partners. If it’s cleared, you can manually replicate WINS information with any WINS server on the network.
Static mappings are created for non-WINS clients on the network, which allows their computer names to be registered in WINS. If multiple computers may use the same IP addresses, you might want WINS to overwrite existing entries with information from new registrations. To do this, select the Overwrite Unique Static Mappings At This Server check box. Click OK.
By default, replication partners are configured to use both push and pull replication. In this scenario, you usually don’t want push replication to occur automatically. Instead, you want it to rely primarily on pull replication for automatic updates. Additionally, because partners are configured for both push and pull replication, you can still initiate push replication manually if you need to.
If you want push replication to occur automatically or you want to change the default settings, follow these steps:
Expand the view for the server with which you want to work in the WINS console.
Right-click Replication Partners in the tree view and then choose Properties.
Click the Push Replication tab shown in Figure 19-4.
Push replication can be initiated when WINS starts and when address changes occur. By default, these options aren’t selected. To change this behavior, select the At Service Startup check box or When Address Changes check box, or both.
Number Of Changes In Version ID Before Replication specifies the number of registrations and changes that must take place before pull partners are notified, which triggers database replication. This counter is for local changes only and doesn’t tally changes pulled from other partners. If the field is set to zero, no push replication takes place.
By default, push replication partners use persistent connections. If you don’t want to use persistent connections, clear the Use Persistent Connections For Push Replication Partners check box. Click OK.
Pull replication is the default replication technique for replication partners. Because of this, most of the default pull replication parameters are enabled automatically. If you’d rather use push replication as the primary replication technique, you should enable automatic push replication using the options in the Push Replication tab and then disable pull replication defaults using the Pull Replication tab.
To change pull replication settings, follow these steps:
Expand the view for the server with which you want to work in the WINS console.
Right-click Replication Partners in the tree view and then choose Properties.
Click the Pull Replication tab, shown in Figure 19-5.
Start Time sets the hour of the day when replication should begin. The time is set using a 24-hour clock.
Replication Interval sets the intervals at which scheduled replication should occur, such as every 30 minutes.
Number Of Retries sets the number of times the WINS server will retry a connection to a pull partner in the event of a failed connection.
By default, pull replication starts when the WINS server starts. To change this behavior, clear the Start Pull Replication At Service Startup check box. When it’s cleared, pull replication starts only at the specified Start Time.
By default, pull replication partners use persistent connections. If you don’t want to use persistent connections, clear the Use Persistent Connections For Pull Replication Partners check box. Click OK.
Push and pull partners are needed to replicate WINS databases whenever multiple WINS servers are on a network. Replication partners get their initial settings from the default replication parameters you’ve configured for a server. You must configure replication separately for each WINS server on the network.
To designate WINS servers as push and pull partners, follow these steps:
Expand the entry for the server with which you want to work in the WINS console. This server is the one for which you’ll configure replication partners.
Right-click Replication Partners in the console tree and then select New Replication Partner.
Type the name or IP address of the replication partner in the WINS Server text box. Or click Browse and, in the Select Computer dialog box, search for a computer with which to work.
Click OK. If the server can be contacted, the replication entry is created automatically using the default settings. The server is configured as a push and pull replication partner.
Default settings are used to initialize the parameters for replication partners. You can change these parameters on a per partner basis at any time by completing the following steps:
Expand the entry for the server with which you want to work in the WINS console. This server is the one for which you’ll configure replication partners.
In the console tree, select Replication Partners. This displays current replication partners for the server in the right pane.
In the right pane, right-click the replication partner with which you want to work, and then select Properties.
Click the Advanced tab, shown in Figure 19-6.
The Replication Partner Type drop-down list shows what type of replication is configured for the partner. By default, most clients are set to use both push and pull replication. You can change this behavior by selecting the Push option or the Pull option.
The remaining settings are the same as those discussed previously in the sections of this chapter entitled "Assigning Default Push Replication Parameters" and "Assigning Default Pull Replication Parameters." Note that you can configure only some of the options through the Replication Partners Properties dialog box. Click OK when you’re finished.
Sometimes you might want to immediately update the WINS databases on replication partners. You can do this by forcing immediate database replication with partners or by triggering replication among partners. You can also specify the type of replication to initiate:
Forcing replication with all partners. To force replication with all partners, right-click the Replication Partners folder for the server whose database you want to replicate, and then select Replicate Now.
Triggering push replication with all partners. To start push replication with all partners, right-click the server whose database you want to replicate, and then select Start Push Replication.
Triggering pull replication with all partners. To start pull replication with all partners, right-click the server whose database you want to replicate, and then select Start Pull Replication.
Triggering push or pull replication with an individual partner. To start push or pull replication with an individual partner, go to the WINS console and click the Replication Partners folder for the server whose database you want to replicate. Currently configured partners are displayed in the right pane. Right-click the partner with which you want to replicate the database, and then select Start Push Replication or Start Pull Replication, as appropriate.
You should actively manage the WINS database to maintain the health of WINS name resolution on the network. The sections that follow examine common management tasks.
When the Active Registrations folder is selected in the console tree, the WINS console’s right pane displays the records that you’ve selected for viewing. Each entry represents a record in the WINS databases. At the left side of the entry, you’ll see one of two icons. An icon of a single computer shows that the mapping is for a unique name. An icon with multiple computers shows that the mapping is for a group, domain, Internet group, or multihomed entry. Mappings also show the following:
Record Name. The complete NetBIOS name of the computer, group, or service registered in the database.
Type. The record type associated with this mapping, such as 00h WorkStation.
IP Address. The IP address associated with the mapping.
State. The state of the record, such as active or released.
Static. An X in this column indicates a static mapping.
Owner. The IP address of the WINS server that owns the record.
Version. The database version ID from which the record originates.
Expiration. The time and date the mapping expires. Static mappings have an expiration date of Infinite, which means that they don’t expire (unless they’re overwritten or deleted).
You should periodically clean the WINS database to ensure that old computer names are removed. The process of cleaning the database, called scavenging, is initiated automatically according to the relationship between the Extinction Interval and the Extinction Timeout set in the Server Properties dialog box.
You can also initiate scavenging manually. To do this, right-click the server with which you want to work in the WINS console, and then choose Scavenge Database. When prompted to confirm, click Yes.
On a large network with multiple WINS servers, the databases on different servers can sometimes get out of sync with one another. To help maintain the integrity of the databases, you might want to verify their consistency periodically. You can perform two types of consistency checking: database consistency and version ID consistency.
When you verify database consistency, WINS checks the integrity of database records on WINS servers. To verify database consistency, select the server with which you want to work in the WINS console and then, from the Action menu, select Verify Database Consistency.
When you verify version ID consistency, WINS checks the local records with records on other WINS servers to ensure that the correct record versions are being maintained. To verify version ID consistency, select the server with which you want to work in the WINS console and then, from the Action menu, select Verify Version ID Consistency.
To configure automatic database consistency checks, complete the following steps:
Right-click the server with which you want to work in the WINS console and then select Properties.
In the Database Verification tab, select the Verify Database Consistency Every check box, as shown in Figure 19-7. Then, in the text box provided, type a time interval for the checks, such as every 24 hours or every 48 hours.
Using the Begin Verifying At options, enter the time when you want verification to start. You set the time with a 24-hour clock.
As necessary, set the Maximum Number Of Records Verified Each Period. The default value is 30,000.
You can verify records against servers designated as owners or against randomly selected partners. Random selection works best if you have a very large network and can’t check all the records at any one time. Otherwise, select Owner Servers to verify records on the servers designated as record owners. Click OK when you’re finished.
Best Practices
Don’t forget that consistency checks can use considerable system and network resources. To gain better control over when checks occur, you’ll usually want to check the WINS database in 24-hour increments and then use the Begin Verifying At fields to set a time that occurs after hours. For example, if you set the database checks on a 24-hour cycle and then enter a begin time of 2 hours, 0 minutes, and 0 seconds, WINS will verify the database at 2 A.M. every 24 hours.
Two WINS server tasks that administrators often overlook are backup and restore.
The WINS database isn’t backed up by default. If you have problems with the database, you won’t be able to recover it. To protect against database failure, you should configure automatic backups or run manual backups periodically. To prepare WINS to perform automatic backups, follow these steps:
Right-click the server with which you want to work in the WINS console and then select Properties.
In the General tab, enter the folder path that you want to use for backups in Default Backup Path. Click Browse if you want to search for a folder.
To ensure that backups are created whenever the WINS server is stopped, select the Back Up Database During Server Shutdown check box.
Click OK. Automatic backups will then be performed every three hours. The default location for database backups is %WinDir%System32Wins.
If you have a good backup of the WINS database, you can restore it by completing the following steps:
Select the server with which you want to work in the WINS console.
On the Action menu, select All Tasks, and then select Stop.
On the Action menu, select Restore Database.
In the Browse For Folder dialog box, select the wins_bak subdirectory containing the most recent backup and then click OK.
If the restore is successful, the WINS database is restored to its state at the time of the backup. WINS should be started automatically.
If the restore is unsuccessful, you might need to clear out all WINS files and then start with a fresh database.
If WINS won’t restore using a backup or won’t start normally, you might need to clear out all WINS records and logs and then start with a fresh database. To do this, follow these steps:
Right-click the server with which you want to work in the WINS console and then select Properties.
In the Advanced tab, note the folder path set in Database Path and then click OK to close the Properties dialog box.
Stop the server by selecting the Action menu, All Tasks, and then selecting Stop.
Using Windows Explorer, delete all files in the WINS database folder.
In the WINS console, right-click the server you’re recovering, choose All Tasks, and then select Start. This starts the WINS servers.