Problem Accessing SNA Server from Windows NT RAS Client (107637)

SYMPTOMS

When you attempt to start a 3270 or 5250 session from a Windows NT RAS client (or from a Windows NT computer which was rebooted without being initially connected to a network), the emulator does not start and the following error occurs:

ERROR - The SnaBase service is not started.

Also, once SnaBase is started, the Windows NT user must still be authorized to open a network session to the Windows NT server where SNA Server is running, or the SNA session cannot connect. If this occurs, the 3270 applet displays "No SNA Server found in domain", while the 5250 applet displays error F004 (Comm_Subsystem_Not_Loaded).

CAUSE

When Windows NT starts up, the SnaBase service is configured to autostart. However, if SnaBase cannot initially connect to an SNA Server, SnaBase stops before the user can establish the RAS connection.

If an administrator logs into the computer and the 3270 emulator is started, the SnaBase service is autostarted. However, if a user logs into the computer, the user does not have authority to start a Windows NT service (for example, SnaBase service), so this error occurs.

Also, once SnaBase is started, the user must still have authority to open a network session to the Windows NT computer where SNA Server is running. If a user account exists on the Windows NT computer, the local user password must match the Windows NT domain user password or access is denied.

RESOLUTION

An SNA Server 2.11 update is available to correct this problem. Microsoft has updated the following Windows NT client files to correct this problem:

<snaroot>\SYSTEM\SNABASE.EXE
<snaroot>\SYSTEM\SNADMOD.DLL

With this update applied, SnaBase does not terminate if you add the following registry Value under the HKEY_LOCAL_MACHINE subtree under the following subkey:

   /SYSTEM/CurrentControlSet/Services/SnaBase/  Parameters/ 

   Value Name: TerminateIfNoSponsors
   Data Type:  REG_DWORD
   Data: 0

If this entry is not present, or is set to 1, then SnaBase terminates if it cannot open the sponsor connection.

NOTE: This update is included in SNA Server versions 2.11 SP1 and later.

Without applying this update, it is possible to work around this problem by assigning the following rights to local users so that they have authority to start SnaBase:

For Windows NT Workstation, the local user must be a member of the "Power Users" group.
For Windows NT Servers, the local user must be a member of the "Server Operators" group.

Also, once the SnaBase service is started, the Windows NT user must still have authority to open a network session to the Windows NT computer where the SNA Server is running. When connecting over RAS, a Windows NT user must initially login to the computer using a local user account. When attempting to get a session to the SNA Server, the local user credentials are used to connect to the Windows NT computer where SNA Server is running.

If the user passwords are not synchronized, and if the SNA client is connecting to the server over named pipes, the user can still gain access to the SNA Server by preestablishing a network session to the server before starting their SNA application. To do this, the user can issue the following command:

net use \\<server_name>\ipc$ /user:<domain>\<user_name> *

where <server_name> is the SNA Server, <domain> is the Windows NT domain, <user_name> is the Windows NT user name, and * causes the prompt for the user's Windows NT password.

Problem Accessing SNA Server from Windows NT RAS Client (107637)

SYMPTOMS

CAUSE

RESOLUTION

STATUS