XADM: Exchange Admin Does Not Browse for Exchange Server Computerss

You install the Exchange Server Administrator program on a computer that is not running Exchange Services. When you press the Browse button, the following error message may be returned if no Exchange Server name is provided.

The most common reason for this error message is that the primary domain controller (PDC) for the domain the computer is a member of is not in the same network segment as an Exchange server.

To ensure reliable browsing, do one of the following:

• Provide a default server name before pressing the Browse button.
  
  -OR-
  
  
• Locate an Exchange Server computer on the same network segment as the PDC.

When the Browse button is pressed, Microsoft Exchange Administrator performs the following actions in an effort to return the Exchange Organization hierarchy.

• If a server name was specified in the Administrator program's Connect to Server dialog box before the Browse button was pressed, the Administrator program attempts to use this server name.
  
  
• If no server name was specified, the Administrator program tries to find the Exchange Server computer on the local system.
  
  
• If it fails to find the Exchange Server computer on the local system, the Administrator program tries the default server name in the registry (if one was entered previously through the Administrator program user interface).
  
  
• The Administrator program then tries the RPC Locator service, requesting that it "find" an Exchange Server computer.

The RPC Locator takes the following actions in an effort to find the requested RPC service (Exchange). The following behavior is for Windows NT 4.x.

• The RPC Locator looks in the local RPC Locator cache to see if it has already successfully performed this lookup for an Exchange Server computer. If it has, The RPC Locator returns the answer from cache.
  
  
• If the local computer is a Windows NT Workstation in a Windows NT domain, the RPC Locator then finds a Windows NT domain controller (DC). It looks for a PDC first, and then for backup domain controllers (BDCs).
  
  
  1. If a DC is found, the RPC Locator asks it to find an Exchange Server (consult step 3 to see how a DC finds Exchange Server computer). If the DC returns a success, the RPC Locator adds the response to the RPC Locator cache. The RPC Locator returns the response from the DC (success or failure) to the requesting application (the Exchange Server Administrator program).
     
     If no DC is found, the RPC Locator issues a local broadcast looking for any Exchange Server computers. If any responses are returned from the network, the RPC Locator adds them to the cache and returns the answer to the requesting application.
  2. If no DC is found, the RPC Locator issues a local broadcast looking for any Exchange Server computers. If any responses are returned from the network, the RPC Locator adds them to the cache and returns the answer to the requesting application.
  
  
  
• If the local computer is a Windows NT Domain Controller, or a Windows NT Workstation in a Workgroup, the RPC Locator issues a local broadcast looking for any Exchange Server computers. If any responses are returned from the network, the RPC Locator adds them to the cache and returns the answer to the Exchange Server Administrator program (or the Windows NT Workstation if this request came from a Windows NT Workstation in a Windows NT domain).

When the Exchange Server Administrator program fails to find any Exchange Server computers to obtain the Exchange Organization Hierarchy, it is usually because the PDC is located on a network segment where no Exchange servers exist. Because the Locator Service uses a broadcast-based discovery mechanism, routable protocols such at TCP/IP fail to discover Exchange Server computers unless they are on the same network segment. To ensure reliable browsing, a default server name should be provided prior to hitting the browse button, or an Exchange server should be located on the same network segment as the PDC.