Setting the session keep-alive parameter

You can use the TCP keep-live parameter to set the maximum idle time that the TCP protocol allows before sending a probe to test for an inactive session.

The protocol sends keep-alive requests to the remote client any time the session remains idle for periods longer than the keep-alive value. The idle period is defined by the Session keep-alive timeout parameter in Telnet Properties in iSeries™ Navigator, or a parameter in the CHGTELNA command. When a session appears to be inactive ( no response is received from the remote client to any keep-alive probe) that session is ended, the virtual device associated with the session is returned to the free pool of virtual devices, and the i5/OS^® operating system performs the action set in the QDEVRCYACN system value on the interactive job running on the virtual device. This action affects only named virtual devices. For automatically selected virtual devices (QPADEVxxxx), the interactive job always ends.

The Telnet server defines the keep-alive setting to 600 seconds by default.

This setting takes effect at server startup. In addition to the session keep-alive timeout parameter, you might also want to review the Timeout interval settings in the Inactive Jobs System Values in iSeries Navigator. This Timeout parameter limits the amount of time that any interactive job is allowed to be idle before the i5/OS operating system performs the action set in the QINACTMSGQ system value on the interactive job. In the case of Telnet-connected interactive jobs, an action of *DSCJOB is honored for only named virtual devices. For automatically selected virtual devices (QPADEVxxxx), an action of *DSCJOB causes the interactive job to be ended.

To set the keep-alive parameter for Telnet in iSeries Navigator, follow these steps:

1. In iSeries Navigator, select your system > Network > Servers > TCP/IP.

2. In the right pane, right-click Telnet and select Properties.

3. On the Telnet Properties page, click the Time-Out tab.

4. On the Telnet Properties - Time-Out page, specify the action to take when jobs reach a time-out. You can also specify how long to give an operation before the job times out. You can specify information for both inactive jobs and disconnected jobs.

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