“If you’ve administered any remote Linux machines, then you’re
probably already familiar with SSH. As you may know, SSH provides
secure, encrypted network communication. Utilities like ssh and
sftp, which are based on SSH, protect remote login sessions and
file transfers, respectively, and have largely subsumed similar but
insecure and unencrypted utilities such as ftp, rlogin, rsh, rcp,
and telnet. (In fact, if any of your systems still use telnet, put
down this magazine at once, go disable telnet, install and enable
SSH, and then continue reading…)”