A systems administrator can sit in front of the console of a server and perform any administrative task, but this is not always possible or desirable, because there could be servers in other countries, or even on other continents, that should be administered too. So, it is almost mandatory to be able to administer servers remotely.
6.1 Telnet
Today, the most usual way to connect to a remote Linux server is by using the ssh protocol. Years ago, admins used the Telnet protocol, but the latter has a great disadvantage: it transmits information in clear text, so an attacker can access sensitive ...
