System services are the services that your server will run, and be used. These are what makes your server a server basically, and what brings you customers. Whether your customers be paying users (such as in an ISP), or they be donation users (users that give little or no money towards your server), they are still important. They are the reason that you want a server, so it is important to think of them. Linux offers *MANY* services, here are some of the more common services:
* Shell Services (The Secure SHell (SSH), Telnet, Remote Shell, etc)
* Mail Services (POP3, SMTP)
* Web Services (Web Hosting)
* DNS Services (Domain Name Services)
* FTP Services
* Talk Services (via Talked, enables users logged in to chat with each other)
* Kerberos Services (secure authentication techniques)
Linux offers many other services, of which will be described in detail later. Most of the services lie in the /etc/init.d directory, which is actually a set of start up scripts, but as most services are started at boot, so the /etc/init.d directory would be a good place to start looking for services installed…..you can also try tel netting to known service ports, which are listed as follows:
