Telnet and FTP Connections to IBM Mainframes Unreliable (100697)


The information in this article applies to:

  • Microsoft LAN Manager 2.2
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
Modification Type:MajorLast Reviewed:9/30/2003
Keywords:KB100697
©2003 Microsoft Corporation. All rights reserved.