Linux Services Related Commands

Local Area Network Services

A Local Area Network (LAN) is a method of connecting two or more computer systems over a small area. Most installations that have more than one computer will install a LAN to allow the users to work on several different computers without physically picking up all of their work and moving to the computer they want to work on.
The LAN services are the programs that allow us to use the LAN to perform many tasks between computers. Some of these tasks are the following:
» Copy files from one computer to another. Without a LAN, you would have to make a tape copy of your files, walk it over to the other computer, and reload the tape.
» Log in to another computer from a terminal on the local computer. Normally you would have to actually go to the other computer to log in.
» Execute commands on another computer and see the results locally. Again, you would have to move to the other computer if you did not have a LAN.
» Access files on a remote computer. This means we will use the files on another computer's disk without copying the files to the local disk.

There are Two groups of LAN services

- ARPA Services
- Berkeley Services

ARPA Services
The ARPA Services were first defined by the Defense Advanced Research Projects Agency (DARPA) in the late 1960s. These services became a standard for communicating to many different brands of computers across a single LAN. The ARPA Services that we will discuss are telnet and ftp.
Berkeley Services
DARPA hired the University of California at Berkeley and Bolt, Baranek and Newman (BBN of Massachusetts) to develop these services. In the mid 1970s Berkeley started working with the new UNIX operating system. They eventually developed a more robust set of services to be used between computers running the UNIX operating system. These are now called the Berkeley Services. We will introduce the Berkeley services rcp, rlogin, and remsh.