Manage Learn to apply best practices and optimize your operations.

Telnet connection repeatedly closes

If a Telnet connection to the AS/400 keeps closing, the keep-alive settings may need to be set to lower time limits.

Has anyone ever had this problem? The Telnet connection keeps closing - even if a job is running. It seems to go down every few minutes if no activity and returns back to signon screen. When I boot in safe mode with network support, I get same problem. The IBM rep states that there must be a service running. So, we sent trace dumps to IBM with no response. We have shut down every nonessential service we can find, but we still have the same problem.
Sometimes there is inactivity timer somewhere on the network.

Lower the TCP keep-alive. The keep-alive frame may reset the inactivity timer. Some network components appear to ignore keep-alives.

The iSeries TCP keep-alive is set using the CFGTCP command, option 3. The value must be less than half the value of the idle timer. For example, if the firewall idle timer is 60 minutes, the keep-alive should be set to 29 minutes or less.

Dig Deeper on Remote Access to iSeries

Have a question for an expert?

Please add a title for your question

Get answers from a TechTarget expert on whatever's puzzling you.

You will be able to add details on the next page.

Start the conversation

Send me notifications when other members comment.

Please create a username to comment.