Openssh set of utilities let us create secure, encrypted connections between machines. In this tutorial we will take a look at some of the most useful options we can use to change the behavior of
Openssh daemon in order to make your Linux system administration job easier.
In this article we assume the existence of an already running and accessible server. If you want to know more about Openssh installation, you can take a look at this article on how to install SSH server on Ubuntu Linux.
In this tutorial you will learn:
- How to customize the behavior of the sshd daemon by manipulating options in the main ssh config file
- How to change the default port(s) used by the server
- How to change the address the server listens to
- How to change the maximum SSH login time
- How to allow or deny login as root
- How to change the max login attempts and maximum number of session opened
- How to display a message when user tries to authenticate to the server
- How to Enable/Disable password and pubkey authentication
- How to Enable/Disable HostBasedAuthentication
- Enabling/Disabling X11 Forwarding