Browser Requests

The purpose of the Browser service is to make a list of network resources available to users. To use this resource list, the client computer must know which computer to contact to request a copy of the list.

Figure 3.5 Flow of the Browser Request

The request issued to obtain the list of available network resources is a NetServerEnum API call. This request is sent when net view is entered at the command prompt or when the Map Network Drive dialog box lists the network resources. The client issues the NetServerEnum API call to a backup browser.

If this is the first time that a NetServerEnum API call is issued on the client computer, the computer must first find out which computers are the backup browsers for its workgroup or domain before it can send the API call. The client does this by issuing a GetBackupList datagram to the master browser.

The master browser receives and processes the GetBackupList request. The master browser returns a list of backup browsers active within the workgroup or domain being queried. The client selects the names of three backup browsers from the list and stores these names for future use. The NetServerEnum API call is sent to a backup browser randomly chosen from the three saved names.

If the master browser for the workgroup or domain being queried cannot be found after three attempts, the client will force the election of a new master browser in the domain. The client returns an ERROR_BAD_NETPATH message to the application, indicating that the master browser could not be found.