Understanding Windows Internet Name Service (WINS)

Today, I’ll discuss Microsoft’s Windows Internet Name Service (WINS). Maintaining a WINS server locally can reduce traffic across your router and speed up name resolution. It has many advantages, and it’s easy to set up.

WINS
A WINS server is simply a Windows NT Server computer that runs Microsoft TCP/IP and the WINS server software. A WINS server maintains a database that maps computer names to TCP/IP addresses, which allows users to communicate with other computers while gaining all the benefits of TCP/IP. To install WINS, you must be logged on as an Administrator. To use or configure a WINS server, you must have full administrative rights for that server.

Benefits of a WINS server
Installing and maintaining a WINS server offers the following benefits:

• Name resolution and name registration through a dynamic database
• Centralized management of the computer name database and the database replication policies
• Elimination of the need to manage LMHOSTS files
• Reduction of IP broadcast in your LAN
• Ability to browse domains on the far side of a router without having a local domain controller on the other side of the router

Installing the WINS service
A computer that runs the WINS server should be assigned a fixed IP address. The WINS server computer shouldn’t be a DHCP client. If the WINS server computer has more than one network adapter card, the binding order of IP addresses shouldn’t be changed. To install the WINS service on a Windows NT Server, do the following:

1. Open the Network Applet in Control Panel.
2. Click on the Services tab. A dialog box will show you what services can be installed, as shown in Figure A.
3. Choose the Windows Internet Name Service and click OK.
4. Once you’ve installed WINS, its name will show up in the Services window, as shown in Figure B.
5. Restart your computer so that the change will take effect.

Figure A

A dialog box will show you what services can be installed.

Figure B

Once you’ve installed WINS, its name will show up in the Services window.

The WINS service
The WINS service runs on a Windows NT Server. The WINS Manager is installed automatically for Windows NT Server and for Windows NT computers when the basic operating system is installed. After installation, the WINS service will start up automatically. If you have to start or stop the service manually, do the following:

1. From the Services icon in Control Panel, find the Windows Internet Name Service.
2. Click on the service and choose Start, Stop, Pause, or Continue from the menu that appears.

It’s also possible to start and stop the service with the following commands:

• Net start wins
• Net stop wins
• Net pause wins
• Net continue wins

If you pause WINS, it won’t accept name packets from clients. Thus, you can prevent clients from using WINS, but you can continue to administer, replicate, and scavenge old records.

The WINS Manager
The WINS Manager icon is added automatically when you install the WINS service. You can use this tool to view and change parameters for any WINS server on your network. To configure a WINS server, you must be logged on as a member of the Administrators group for that server.

To open the WINS Manager, go to Start | Programs | Administrative Tools | WINS Manager. Or you can type Start Winsadmn at the command prompt. You also can include a WINS server name or IP address with the command; you can type Start Winsadmn 10.5.5.1 or Start Winsadmn Winsserver.

If the local computer is running WINS, that WINS server is opened automatically; otherwise, the Add WINS Server dialog box will appear. WINS Manager will list some basic statistics for the selected server. To display additional statistics, click Detailed Information on the Server menu.

WINS Manager statistics
When you open the WINS Manager, a window will display statistics for the activities on the selected WINS server, as shown in Figure C. You can view the following statistics from here:

• Server Statistics
• Last Replication Times
• Total Queries Received
• Total Releases
• Total Registrations

Figure C

This window displays statistics for the activities on the selected WINS server.

To refresh the statistics that are displayed, you can click on Refresh Statistics from the View menu. You also can choose Auto Refresh from the Server Statistics menu under Preferences. You can clear the statistics and start fresh by choosing Clear Statistics from the View menu.

To view more detailed information, choose Detailed Information from the Server menu. You’ll still see basic information about the connection, including the server status and the administrative rights of the current user:

• WINS Server Address
• Last Scavenging Times
• Unique Registrations
• Group Registrations

WINS Manager preferences
To set preferences for the WINS Manager, choose Preferences on the Options menu. To see all of the available preferences, click Partners. You can see examples of the following information in Figure D.

Figure D

You can view and set all of the available preferences for the WINS Manager.

You can click on the Address Display option to display information by computer name, IP address, or a combination of both. You can use Auto Refresh to specify the number of seconds between refresh actions. If you choose LAN Manager-Compatible, computer names will adhere to the LAN Manager naming convention. Clicking Validate Cache Of Known WINS Servers At Startup Time will force the system to query the list of servers for available servers each time the system starts. If you click Confirm Deletion Of Static Mappings And Cached WINS Servers, a warning message will appear whenever you delete a static mapping or the cached name of a WINS server. In the Start Time box, you can specify a time for replication with new pull partners. Then, you can specify values for the Replication Interval, which will indicate how often data replicas are exchanged between the partners. Type the number of registrations and changes that can occur locally before the server sends a replication trigger (when it’s a push partner in the Update Count box).

Configuring WINS servers
Configuring multiple WINS servers will increase server availability and balance the load among servers. Each WINS server must be configured with at least one other WINS server as its replication partner. You also must configure threshold intervals for triggering database replication for each WINS server.

To configure your WINS server, click Configuration on the Server menu. You can change the following items, which appear in Figure E:

• Renewal Interval
• Extinction Interval
• Extinction Timeout
• Verify Interval

Figure E

To configure your WINS server, change these settings.

If you want your WINS server to pull replicas of new WINS database entries from its partners, click Initial Replication in the Pull Parameters options and type a value for Retry Count. If you want to inform partners of the database status when the system is initialized, click Initial Replication in the Push Parameters group. To inform partners of the database status when an address changes in a mapping record, choose Replicate On Address Change.

Advanced WINS server configuration options
Every WINS server must be a push partner or pull partner with at least one other WINS server. WINS servers communicate among themselves to replicate their databases. Replication is carried out among replication partners, rather than having each server replicate to all the other servers. Replication is triggered when a WINS server polls another server. Polling begins at system startup and repeats at the specific time interval for periodic replication. Replication is also triggered when a WINS server reaches a threshold set by the administrator. An administrator also can cause a replication immediately or at a specified time.

Configuring replication partner properties
When you designate a replication partner, you must specify parameters for push partners and pull partners that determine when replication will begin. Click the server that you want to configure in the WINS Server list of the Replication Partners dialog box. To indicate the replication option you want, specify whether the server will be Push Partner or Pull Partner and click Configure.

Defining push partners
You can determine how many additions and updates will be made to records in the database before the changes result in replication. You can specify a number in the Update Count box of the Push Partner properties. In the Start Time box of the Pull Partner properties dialog box, type a time that indicates when replication will begin. The Replication Interval box allows you to type a time that indicates how often replications will occur.

Adding and deleting replication partners
To add a replication partner for a WINS server, do the following:

1. Click Replication Partner on the Server menu.
2. Click Add, type the name or IP address of the WINS server that you want to add to the list (as shown in Figure F), and click OK.

Figure F

Type the name or IP address of the WINS server that you want to add.

If the server can be found, it will be added to the WINS Server list.

To delete a replication partner, do the following:

1. From the Server menu, click Replication Partners.
2. Choose one or more servers in the WINS Server list and click Delete.

Triggering replication between partners
It’s possible to replicate the database between the push partners or pull partners immediately. You should begin replication immediately after you make a series of changes, such as entering a range of static address mappings. To send a replication trigger, choose Replication Partners from the Server menu. Choose the WINS servers to which you want to send a replication trigger and click Push or Pull (depending on whether you want to send the trigger to push partners or pull partners). You also can choose Replicate Now in the Replication Partners dialog box.

Adding static mappings to the WINS database
The WINS Manager allows you to add static mappings to the WINS database. This feature is important for such things as your Domain Controllers or Member Servers. To add a static mapping, do the following:

1. From the Mappings menu, choose Static Mappings.
2. When the Static Mappings dialog box appears (as shown in Figure G), choose Add Mappings.
3. Type the computer name of the system for which you are adding the static mapping.
4. Type the IP address for the computer.
5. You must choose a type of entry. The options are Unique, Group, Domain Name, Internet Group, and Multihomed.
6. If you specified a Domain Name, Internet Group, or Multihomed type, you’ll be prompted to input additional information.
7. Choose Add to complete the static mapping process.

The mapping takes place immediately.

Figure G

Choose Add Mappings from the Static Mappings dialog box.

Importing static mappings
You can import entries for static mappings from any file that has the same format as the LMHOSTS file. Scope names and keywords other than #DOM are ignored. To import a file that contains static mapping entries, do the following:

1. Click Import Mappings in the Static Mappings dialog box.
2. Specify the filename that you want to import by typing its name in the box or by selecting it from the list. Choose OK to import the file.

A static mapping will be created for each computer name and address in the file. If the #DOM keyword is included in any record, a special group is created, and the address is added to that group.

Editing static mappings
You can change the IP addresses in static mappings that are owned by the WINS server you are currently administering. To edit a static mapping entry, do the following:

1. In the Static Mappings dialog box, click the mapping that you want to change and click Edit Mapping.
2. Type a new address for the selected computer and click OK.
3. If the new address that you entered is already in the database, a message will ask you to enter a different address.

The changes that you make to the WINS database will take effect immediately.

Database maintenance
You need to clean and back up the WINS database periodically—you should clear the database of released entries or old entries. This process is called scavenging. It’s performed automatically over intervals that are defined by the relationship between the Renewal and Extinction intervals, which in turn are defined in the Configuration dialog box.

WINS Manager provides the tools that you need in order to scavenge the database manually. To scavenge the WINS database, choose Initiate Scavenging from the Mappings menu. You’ll receive a message that scavenging has been queued.

WINS database structure
The files that you need in order to administer WINS are stored in the \\%SystemRoot%\System32\WINS folder.

• Jet.log: This file contains all transactions that are performed with the database. WINS uses it to recover data, if necessary.
• System.mdb: This file holds information about the structure of its database.
• Wins.mdb: This is the actual WINS database file.
• Winstmp.mdb: This is a temporary file that WINS creates. It may remain in the WINS folder after a crash.

Backing up the WINS database
The WINS Manager provides backup tools, which you can use to back up and restore the WINS database. After you specify a backup folder for the database, WINS uses the specified folder and performs complete database backups every three hours. To back up a WINS database, do the following:

1. From the Mappings menu, choose Backup Database.
2. Type the location to which you want to save the backup files and click OK. You shouldn’t specify a network drive as the backup location.

Restoring a WINS database
In case of database corruption, the WINS database can be restored from the backup. To restore a WINS database, do the following:

1. From the Mappings menu, choose Restore Database.
2. Type the location where the backup files are stored and click OK.

Compacting the WINS database
After WINS has been running for a while, the database might need to be compacted in order to improve WINS performance. As a general rule of thumb, you should compact the WINS database whenever it approaches 30 MB. To compact the WINS database, do the following:

1. Stop the WINS service.
2. Run the Jetpack.exe program, which is found in the \%SystemRoot%\System32 folder.
3. Restart the Windows Internet Name Service on the WINS server.

Conclusion
A WINS server can become a valuable asset to your network. The WINS Manager is the tool that you need in order to back up, restore, and maintain your WINS database. You can speed up name resolution on your network by having a local WINS server. For the amount of time and resources that are required to run a WINS server, it’s a good investment.