The software described in this documentation is either in Extended Support or Sustaining Support. See https://www.oracle.com/us/support/library/enterprise-linux-support-policies-069172.pdf for more information.
Oracle recommends that you upgrade the software described by this documentation as soon as possible.
The Secure Shell (SSH) allows protected, encrypted communication with other systems. As
SSH is an entry point into the system, disable it if it is not required, or alternatively,
edit the /etc/ssh/sshd_config file to restrict its use.
For example, the following setting does not allow root to log in using
SSH:
PermitRootLogin no
You can restrict remote access to certain users and groups by specifying the
AllowUsers, AllowGroups, DenyUsers,
and DenyGroups settings, for
example:
DenyUsers carol dan AllowUsers alice bob
The ClientAliveInterval and ClientAliveCountMax
settings cause the SSH client to time out automatically after a period of inactivity, for
example:
# Disconnect client after 300 seconds of inactivity ClientAliveCountMax 0 ClientAliveInterval 300
After making changes to the configuration file, restart the sshd
service for your changes to take effect.
For more information, see the sshd_config(5) manual page.