Re: Troubleshooting interrupted Telnet connections

[Scott Klement <midrange-l@xxxxxxxxxxxxxxxx>]

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"


> TCP keep alive . . . . . . . . . TCPKEEPALV     10

I don't know whether the IBM i TELNET server uses the TCP keepalives or 
not.  Bear in mind that this is something that can be turned on or off 
on a per-socket basis.


>   Session keep alive timeout . . . TIMMRKTIMO     120

This one is definitely used by TELNET, but may not affect the "idle 
time" calculation in your firewall/router?   But your router should 
allow you to turn off the timeouts...