We have recently upgraded our server hardware (IBM X3100 M4) and OS (SLES 11 SP2). Since this upgrade, we have had issues with dropped telnet connections.
We have approxiamately 130 filed offices, all of which have their own local server. Users use Glink terminal emulator (which we have used for 15+ years) on a PC running Windows XP (which we have been running for several years) to establish a telnet connection to the local server. When the user has logged in, Glink passes a command to the server in the form "program_name; exit", and the session is associated with a pts.
Previous to the upgrade (and even now, for the most part), this performs as expected; program_name executes and, upon successful termination of the program, the user is logged out.
What we are seeing now, at least once a day and at all field offices, a single workstation (and not always the same one) will lose the telnet connection. A ps -ef still shows program_name running (still associated with the workstation), but no longer associated with a pts. Currently, for lack of a better solution, we have a cron job that runs every other minute that checks for and, if found, kills this orphaned session.
This Glink / Windows XP arrangement has worked well forn us in the past under various hardware configurations using AIX 5.0, SLES8, and SLES 9 SP2. Are there some TCP parameters that perhaps need to be tweaked under SLES 11 that are causing this issue?