RPC Client Does Not Respond After SAP Name Resolution (240423)


The information in this article applies to:

  • Microsoft Windows 95
  • Microsoft Windows 98
  • Microsoft Windows 98 Second Edition
This article was previously published under Q240423

SYMPTOMS

An program that requests Remote Procedure Call (RPC) services on a named server by using the SPX protocol may encounter apparent name resolution problems, given that subsequent attempts using the network address of the same server succeed. The specific situation discussed in this article can be identified only with a network trace. The message traffic leading up to this situation is as follows:
  • The client issues an IPX Service Advertising Protocol (SAP) broadcast of a Nearest Service query to find a file server.
  • The server whose name was submitted to RPC replies with an IPX SAP Nearest Service response.
  • The client issues a NetWare Core Protocol (NCP) connect packet to the server.
  • The server responds with an NCP reply indicating a successful connection.
  • The client stops communicating with the server and does not issue the expected NCP Read Property Value response against the NET_ADDRESS of the server.
  • RPC returns error 27 (RPC_S_SERVER_UNAVAILABLE) to the running program. The error message associated with this error is "The RPC server is unavailable."
This problem has been reported to occur on Windows 98 clients, as well as Windows 95 clients with Distributed Component Object Model (DCOM) version 1.2, or Microsoft Internet Explorer version 4.01 installed.

CAUSE

The cause is an incorrect status returned to the RPC client by the socket provider following a successful SAP transaction to verify that the named server provides the requested RPC service.

WORKAROUND

If you encounter this problem, you can use the network address of the RPC server in place of the server name. The possibility of substituting the address for the name is dependent on the program in use, which may or may not allow you this level of control.

MORE INFORMATION

The following information does not provide minimum and sufficient criteria to reproduce the reported problem. It is included to define a sample of the basic network configuration underlying the reported problem.
  • Software: the MSDN Platform SDK RPC "Hello" sample programs
  • Server: Microsoft Windows NT with NWLink IPX/SPX-compatible transport
  • Client: Windows 95/Windows 98 with the Client for NetWare Networks and IPX/SPX Compatible Protocol installed
Commands to run:

Server: hellos -p ncacn_spx -e 2000

Client: helloc -p ncacn_spx -e 2000 -n servername

Replace servername with the actual name of the Windows NT server.
Modification Type:MinorLast Reviewed:12/17/2004
Keywords:kbnetwork kbprb KB240423
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