how to modify automatic logout about console, WebUI and SSH??

can you try b sshd help?

i do not have 9.4.x. the following is from 10.2.4.

SSHD(1)                          BIG-IP Manual                         SSHD(1)

NAME
       sshd command - Configures the Secure Shell (SSH) daemon for the BIG-IP system.

SYNTAX
       Use this command to configure the sshd daemon on the system.

CREATE/MODIFY
       Important: If you are assigned a user role that allows you to create objects, and you are assigned
       access to all partitions, then before you create an object in a specific partition, you must use
       the bigpipe shell command to set your Write partition to the partition in which you want to create
       the object. For more information, see the Configuring Administrative Partitions and Managing User
       Accounts chapters in the TMOS Management Guide for BIG-IP Systems.

       Note: You must enter the values for the loglevel argument using the exact case shown below. In
       other words, to assign a log level of ERROR, you use the syntax: bigpipe sshd loglevel ERROR.

        bigpipe sshd [{]  [}]
           ::=
             allow ( │ none) [add │ delete]
             banner (enable │ disable)
             banner text ( │ none)
             inactivity timeout 
             include ( │ none)
             login (enable │ disable)
             loglevel (QUIET │ FATAL │ ERROR │ INFO │ VERBOSE │ DEBUG │ \
               DEBUG1 │ DEBUG2 │ DEBUG3)

DISPLAY
        bigpipe sshd [show [all]]
        bigpipe sshd list [all]
        bigpipe sshd allow

can you try b sshd help?

i do not have 9.4.x. the following is from 10.2.4.

SSHD(1)                          BIG-IP Manual                         SSHD(1)

NAME
       sshd command - Configures the Secure Shell (SSH) daemon for the BIG-IP system.

SYNTAX
       Use this command to configure the sshd daemon on the system.

CREATE/MODIFY
       Important: If you are assigned a user role that allows you to create objects, and you are assigned
       access to all partitions, then before you create an object in a specific partition, you must use
       the bigpipe shell command to set your Write partition to the partition in which you want to create
       the object. For more information, see the Configuring Administrative Partitions and Managing User
       Accounts chapters in the TMOS Management Guide for BIG-IP Systems.

       Note: You must enter the values for the loglevel argument using the exact case shown below. In
       other words, to assign a log level of ERROR, you use the syntax: bigpipe sshd loglevel ERROR.

        bigpipe sshd [{]  [}]
           ::=
             allow ( │ none) [add │ delete]
             banner (enable │ disable)
             banner text ( │ none)
             inactivity timeout 
             include ( │ none)
             login (enable │ disable)
             loglevel (QUIET │ FATAL │ ERROR │ INFO │ VERBOSE │ DEBUG │ \
               DEBUG1 │ DEBUG2 │ DEBUG3)

DISPLAY
        bigpipe sshd [show [all]]
        bigpipe sshd list [all]
        bigpipe sshd allow

What is your question? The default is 1200 seconds (20 minutes) and the idle time cannot be disabled but you can modify. modify sys sshd inactivity-timeout