Exchange System Attendant on an RPC Proxy Server That Is a Front-End Server
When you configure the front-end server as an RPC over HTTP front-end server, the system attendant immediately scans the directory to gather information for the ValidPorts registry entry. Additionally, the system attendant scans the directory periodically to update the configuration in the ValidPorts registry entry. By default, the system attendant performs this scan every 15 minutes.
The following registry key controls how frequently the directory is polled:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MSExchangeSA\Parameters
DWORD: HTTPFEPollingInterval
Default = 15 minutes, minimum = 1
During its next poll interval, the system attendant automatically finds any new back-end servers that you configure as RPC over HTTP back-end servers.
The system attendant writes the following information to the ValidPorts registry entry. This information varies depending on the version of the back-end Exchange server.
| Product Version | Information in the ValidPorts registry entry |
|---|---|
Exchange Server 2003 with no service packs |
<NetBIOS name of server>:6001; <NetBIOS name of server>:6004; <Fully Qualified Domain Name (FQDN) of server>:6001; <FQDN of server>:6004 |
Exchange Server 2003 Service Pack 1 (SP1) or subsequent service packs |
<NetBIOS name of server>:6001-6002; <NetBIOS name of server>:6004; <FQDN of server>:6001-6002; <FQDN of server>:6004 |
The product version difference in the information that is written to the ValidPorts registry entry reflects changes in the referral service of the Directory Service Proxy (DSProxy) component that were introduced in Exchange Server 2003 SP1. If a back-end server has Exchange 2003 SP1 or subsequent service packs installed, the Exchange front-end server allows access to the referral port of DSProxy (6002) for faster directory access.
For more information about DSProxy, see RPC over HTTP Interactions on the Back-End Servers.