How Windows Publishes Network Resources

When you share a network resource, such as a folder or printer, Windows communicates using several protocols to make other computers on the network aware of the resource. To communicate with versions of Windows prior to Windows Vista, the Server service notifies the Computer Browser service when new shares are created or deleted, and the Computer Browser service sends the announcements over NetBIOS.

To announce resources to other computers running Windows Vista and Windows 7 using WS-Discovery, Windows 7 uses the Function Discovery Resource Publication (FDRP) service. Although FD is responsible for discovering shared resources on a network when the computer is acting as a client, FDRP is responsible for announcing resources when the computer is acting as a server. The primary functions are:

• Sends a HELLO message for each registered resource on service startup.
• Sends a HELLO message whenever a new resource is registered. Responds to network probes for resources matching one of the registered resources by type.
• Resolves network requests for resources matching one of the registered resources by name.
• Sends a BYE message whenever a resource is unregistered.
• Sends a BYE message for each registered resource on service shutdown.

The HELLO message includes the following information:

• Name
• Description
• Whether the computer is part of a workgroup or domain
• Computer type, such as desktop, laptop, tablet, Media Center, or server
• Whether Remote Desktop is enabled and allowed through Windows Firewall
• Folder and printer shares with at least Read access for Everyone if file sharing is enabled and allowed through Windows Firewall. Specifically, administrative shares are not announced. For each share, the following information is included:
  • Path
  • If applicable, the folder type (such as documents, pictures, music, or videos)
  • The share permissions assigned to the Everyone special group

FDRP is primarily intended for home networks, where ease of use is typically a requirement and networks are unmanaged. In corporate computing environments, where there can be a large number of computers on a single subnet and the network is managed, FDRP is not recommended because the traffic might become a nuisance. By default, FDRP is enabled in a workgroup and disabled in a domain environment.