SSH and OpenSSH overview and base configuration

SSH is an acronym for Secure Shell Host. It started to spread by replacing traditional telnet usage, which was a remote login protocol that used no encryption for connecting to hosts, so the credentials that were used for logging in were transmitted in plain text. This means that anyone who had a system between the user terminal and the remote server could intercept the username and password and use that information to connect to remote systems. This is similar to what happens when credentials are transmitted to a web server via HTTP and not HTTPS.

With SSH, a secure channel is created between the client and the target host, even if the connection is performed over untrusted or insecure networks. Here, the SSH channel that's created is secure and no information is leaked.

OpenSSH provides both a server and a client (the openssh-server and openssh-clients packages in Red Hat Enterprise Linux (RHEL) that can be used to connect...