Friday, March 18, 2011
Understand the Computer Browser Service
To collect and display all computers and other resources on the network, Windows NT uses the Computer Browser service. For example, opening Network Neighborhood displays the list of computers, shared folders, and printers; the Computer Browser service manages this list. Every time Windows NT is booted, this service also starts. Computer Browser is responsible for two closely related services: building a list of available network resources and sharing this list with other computers. All Windows NT computers run the Computer Browser service, but not all of them are responsible for building the list. Most computers will only retrieve the list from the computers that actually collect the data and build it. Windows NT computers can therefore have different roles. Let's take a look at them:
Domain master browser: The primary domain controllers (PDCs) handle this role. The PDCs maintain a list of all available network servers located on all subnets in the domain. They get the list for each subnet from the master browser for that subnet. On networks that have only one subnet, the PDC handles both the domain master browser and the master browser roles.
Master browsers: Computers maintaining this role build the browse list for servers on their own subnet and forward the list to the domain master browser and the backup browsers on its own subnet. There is one master browser per subnet because all browsing works on broadcasting system.
Backup browsers: These computers distribute the list of available servers from master browsers and send them to individual computers requesting the information. For example, when we open Network Neighborhood, our computer contacts the backup browser and requests the list of all available servers.
Potential browsers: Some computers don't currently maintain the browse list, but they're capable of doing so if necessary, which designates them as potential browsers. If one of the existing browsers fails, potential browsers can take over.
Nonbrowsers: These are computers that aren't capable of maintaining and distributing a browse list.
Most browsing tasks are performed automatically without any help from the administrator. The election process, which determines which computer will function as the master browser, takes place when:
• The primary domain controller (PDC) is booted.
• A backup browser is unable to obtain an updated browse list from the existing master browser.
• A computer is unable to obtain a list of backup browsers from the master browser.
• Only the master browser is elected. As we explained last time, the domain master browser is always the PDC. If the PDC is unavailable, there is no domain master browser.
There are times when we might want to modify this behavior and interfere with the browsing process. We can do this by tweaking two registry entries. Open the Registry Editor and navigate to:
Yes is the default setting for all Windows NT domain controllers and configures the computer to function as a backup browser or a master browser. Setting this entry to No will configure the computer to function as a nonbrowser. Selecting Auto will configure the computer to become a potential browser, backup browser, or a master browser. This is the default for all Windows NT servers that are not domain controllers.
The default setting for all Windows NT computers is False. Setting this value to True assigns the computer a higher election criteria value than it would normally have, giving the computer an advantage in a browser election and causing it to become the master browser if all other computers use the same operating system.
Here's a common problem: Sometimes we can't see all the servers in Network Neighborhood. We know the servers are still there because we can access them by typing \\computername in the Run dialog box. In this instance, the most obvious problem is the Computer Browser service.
We also encounter such problems One very beautiful problem I would like to share with all of you. In our network we found several times that very limited system has been shown in our Network Neighborhood screen.
Even though we set all the tuning parameters in registries still the problem exist. But if we restart any NT machine after a day problem disappear.
After several days struggle we found that a Win98 system is master server but my knowledge didn’t allow me to except this fact we also observed that only those Win98 pc became a master server in which we are not able to disable the browser function.
Here a question arises is that why it happens finally I concluded that because Win98 ed 2 are newer one than NT4 that’s why when user switch on Win98 system it wins a browser election and became a master browser to tolerate with this problem its essential that disable browser function in all Win98 Pcs.