Ssh idle out disconnects on SCO Unix OpenServer or Unixware

Problem: ssh session is getting disconnected after idle out time.

Cause: Most firewalls will drop idle connections after a period of time which can interfere with ssh daemon default TCPKeepAlive mechanism.

Solution: Replace the TCPKeepAlive with ClientAliveInterval (in seconds) in /etc/ssh/sshd_config

#Firewall workaround
# turn TCPKeepAlive off and check the client every 5 minutes
# TCPKeepAlive no
# fail after 6 tries (30 minutes)
ClientAliveInterval 300
ClientAliveCountMax 6

Then restart sshd or reboot.