Knowledge Base

Telnet and FTP Connections to IBM Mainframes Unreliable

Article ID: 100697

Article Last Modified on 9/30/2003

APPLIES TO

This article was previously published under Q100697

SYMPTOMS

Difficulty connecting to IBM mainframes with Microsoft TCP/IP utilities such as Telnet and FTP.

CAUSE

IBM mainframes appear to expect the TCP/IP "push" bit to be set on all frames for Telnet and FTP. The Microsoft LAN Manager TCP/IP stack and utilities don't always set the "push" bit by default.

RESOLUTION

The Microsoft Windows for Workgroups TCP/IP stack recognizes a new PROTOCOL.INI parameter for more reliable Telnet and FTP sessions to IBM mainframes. Add this line to the [tcpip_xif] section: 
   forcepushbit = 1

Additional query words: wfw wfwg 2.20 session hang RFC 793 smtp gateway 2.2

Keywords: KB100697


Send feedback to Microsoft

© Microsoft Corporation. All rights reserved.