RE: Troubleshooting interrupted Telnet connections

That is interesting not on the Cisco VPN client. The ugly part is the
session is active and I am working, usually running some procedure that
locks the for a while, then the session drops. Guess in the IP world,
there is no activity. Turning off the Cisco VPN client State full
firewall keeps the session from dropping. I always figured that the
iSeries used a separate connection to verify the client. Never thought
that the firewall saw the keep alive packets and dropped them.

Thank you for lesson.


Chris Bipes
Director of Information Services
CrossCheck, Inc.

-----Original Message-----
From: midrange-l-bounces@xxxxxxxxxxxx
[mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Scott Klement
Sent: Friday, April 23, 2010 10:09 AM
To: Midrange Systems Technical Discussion
Subject: Re: Troubleshooting interrupted Telnet connections

Hello,

OS400 keep alive uses a different connection I think to see if the
remote client is still there.

It shouldn't. That's not how either TCP or TELNET works. Keep alives
are part of the TCP connection. The TELNET ones are just data sent over

a TCP connection.

I know if I have the State full firewall enabled with my Cisco VPN
client, my tn5250 sessions drop.

The Cisco VPN client may be smart enough to ignore keepalives. A lot of

tools that drop idle connections are smart enough that they don't
consider a keepalive to be "activity"