XCLN: Troubleshooting IPX/SPX Connections

• Microsoft Exchange Windows 3.x client, versions 4.0, 5.0
• Microsoft Exchange Windows NT client, versions 4.0, 5.0
• Microsoft Exchange Windows 95/98 client, versions 4.0, 5.0

SYMPTOMS

The client cannot connect to a computer running Microsoft Exchange Server using IPX/SPX. Remote procedure call (RPC) PINGs work, but not with security. In addition, you may receive the following error message:

Your Microsoft Exchange Server is unavailable.

CAUSE

The IPX/SPX protocol is not configured correctly for Microsoft Exchange Server access.

RESOLUTION

The following is a checklist you can use to ensure that the IPX/SPX protocol is correctly configured:

1. Make sure IPX/SPX (NWLINK) is installed on the computer running Microsoft Exchange Server, the computer running the Microsoft Exchange client, and any primary (PDC) or backup (BDC) domain controllers.



2. Gateway Services for NetWare (GSNW) must be installed and running on the computer running Windows NT Server and Microsoft Exchange Server. This is required so that the server broadcasts SAP 0x640. The RPC Service and the RPC Locator services must be running. Additionally, there must be either a NetWare or a Windows NT Server computer running File and Print Services for NetWare (FPNW) and installed on the network to maintain the Exchange Server computer's address in its SAP database.
   
   If this is a routed IPX environment, make sure SAP 0x640 is not being filtered on the router.



3. Check IPX/SPX frame types. It is recommended that you manually set this on both the computer running Exchange Server and its clients. (On the computer running Windows NT Server, go to the Network Control Panel and click IPX/SPX. Click Properties, click to select "Manual Frame Type Detection", and add the appropriate frame type, such as 802.2.)



4. If "Manual Frame Type Detection" is selected, make sure the network number is the same for every server on the IPX subnet. If an Internal network number is configured, it must be a unique network number.



5. Make sure the packet size is the same on Token ring, or a smaller size on Ethernet. In the Net.cfg file on computers running Windows for Workgroups or Windows 3.1, make sure MaxFrameSize equals an appropriate size, such as 1,496. The frame of client computers running Windows 95 or Windows NT Workstation should be adjusted to the maximum frame size for their network topology.



6. On computers running Windows for Workgroups or Windows 3.1, open the Net.cfg (or Shell.cfg) file and make sure IPX packets=50, IPX Sockets=50, and READ ONLY COMPATIBILITY=OFF.

1. Run Rpings.exe on the server. Make sure there are valid endpoints (set for use) for ncadg_ipx and ncacn_spx.



2. Run Rpingc32.exe on client computers running Windows 95 or Windows NT Workstation, to make sure IPX/SPX can complete an RPC PING to the server. Also try this "with security."



3. On the client, try logging in without using default network security. (On the Tools menu, click Services. Select Microsoft Exchange Server, click Properties, and then click Advanced. Click to clear the "Use network security during logon" check box.) This forces a prompt to appear for you to enter Windows NT Server domain, account, and password information.



4. Move ncacn_spx to be first in the binding order.
   
   For additional information about changing the RPC binding order, please see the following Microsoft Knowledge Base article:




Q163576 XGEN: Changing the RPC Binding Order

5. Update the IPX/SPX drivers. The latest version of the drivers, as of 6/98, is VLM 1.21 and can be obtained from Novell.
   
   
   NOTE: Many old VLM NetWare drivers do not connect to Microsoft Exchange Server. On computers running Windows for Workgroups 3.11 or Windows 3.1, you may need updated versions of Nwipxspx.dll and Nwcalls.dll.



6. If there is a Microsoft Proxy Server installed on the network, try turning off DNS. (In the Network Control Panel, select TCP/IP and click Properties. Click the DNS Configuration tab, and click Disable DNS.) You can keep the TCP/IP functionality by adding to the hosts file. In the hosts file, make one entry for the Microsoft Exchange Server as <IP address> <Microsoft Exchange Server Name, or NetBIOS name>, and one for the Proxy Server as <IP Address> <proxy server fully qualified domain name, such as server.company.com>.



7. Check the Event Viewer on the computers running Windows NT Server (the computers running Microsoft Exchange Server, the PDC, or the BDC servers) for errors.

MORE INFORMATION

For more information, see the following article in the Microsoft Knowledge Base, the Microsoft Exchange Installation Guide - the Introduction and Appendix A, and the Readme.wri file on the Microsoft Exchange Client Software compact disc:

Q136516 XCLN: Improving Windows Client Startup Times

Additional query words: exclnfaqold

Keywords : XCLN
Version : WINDOWS:4.0,5.0
Platform : WINDOWS
Issue type : kbprb