INFO: DCOM Does Not Support Any Datagram (UDP) Protocols (242022)

MORE INFORMATION

DCOM exposes its security model through Remote Procedure calls (RPC) and Security Support Provider Interface (SSPI). Beginning with Windows 2000 adn Windows XP , DCOM supports a variety of Security Providers (SSP), including the following:

• Kerberos protocol SSP
• Microsoft Windows NT LAN Manager (NTLM) SSP
• Simple GSS-API Negotiation Mechanism (Snego) SSP

Because some of these SSPs do not support datagram protocols, DCOM using RPC and SSPI use the connection-oriented protocols.

To eliminate a 30-45 second delay when connecting to a DCOM server on Windows 2000 and Windows XP, move "Connection-oriented TCP/IP" protocol to the top of the DCOM protocols list in the DCOMCNFG/Default Protocols tab on Windows NT 4.0-based clients. You must restart the computer for the change to take effect.

NOTE: This delay occurs only if you haven't recently connected to the target server (because DCOM Service Control Manager caches RPC binding handles, any client re-activating the server by using the same security context uses the cached binding handle, and therefore uses the protocol that worked in the past).

The following is a list of the transport protocols that DCOM uses, depending on the client/server platform:

Platform	Protocol
Windows NT 4.0 <---> Windows NT 4.0	Connection-oriented or datagram protocols
Windows 2000 <---> Any	Any of the connection-oriented protocols
Windows XP <---> Any	Any of the connection-oriented protocols
Microsoft Windows 95 or Microsoft Windows 98 <---> Any	Connection-oriented TCP/IP
DCOM for UNIX <---> Any	Connection-oriented TCP/IP