Symptoms of multihomed browsers

http://support.microsoft.com/default.aspx?scid=kb;EN-US;191611
 NT5.2 windows up to win20003
The computer browser service was first introduced in Microsoft Windows for Workgroups 3.1. The purpose of the browser service is to collect and report information about the existence of other computers on the network that share file, print, and other resources. The browser service greatly reduces the number of server announcements on a network. The browser service also reduces the overhead of every network client and server because clients and servers do not have to maintain their own list of server resources.

The browser service was originally designed for computers connected on a single-segment local area network (LAN) using a nonroutable protocol, such as NetBIOS Extended User Interface (NetBEUI). If a client requested a list of servers from a multihomed browser server, the browser service would provide only the list of servers gathered on the network adapter that received the browse request. This was done because it could not be assumed that a client would be able to connect to servers on the other segment. When you use a nonroutable protocol, such as NetBEUI, a client also must be multihomed to connect to a remote server. When you use a routable protocol, such as Transmission Control Protocol/Internet Protocol (TCP/IP), an infrastructure of routers must be in place for the physical connection to be possible. Also, there must be an Lmhosts file that is configured for all clients that have the potential to connect to the remote servers.

Microcomputer networks have since evolved into much larger environments that require routable protocols and distributed NetBIOS naming servers, such as the Windows Internet Naming Service (WINS) for NetBIOS communication. With the growth of segmented LANs, the browser service has been updated to accommodate the TCP/IP protocol in a domain environment. To obtain a single domain-wide browse list, the primary domain controller (PDC) merges all the browse lists that are gathered by the master browsers on each segment across the wide area network (WAN). This role is called the domain master browser and can be performed only by the PDC. WINS allows clients to easily access remote servers throughout the WAN, and each PDC periodically contacts the WINS server to obtain a list of all the domains throughout the network. This allows for full browsing of server resources throughout the WAN.

The evolution of networking has also increased the number of servers and clients that have more than one network adaptor. Multihomed servers can create unexpected and undesirable effects with the browser service.