UNIX System Management: Using Network services

To complete this chapter, you can do the following things:

Describe different network services in Unix

Understanding the capabilities of a local area network (LAN)

Locate the host name of the local host and the hostname of the other systems in the LAN.

Use the Arpa/http://www.aliyun.com/zixun/aggregation/33795.html >berkeley service to perform remote logins, remotely file transfers, and remote command execution.

11.1 What is a LAN?

A local area network (LAN) connects two or more computers in a small area. More than one computer is typically installed on a LAN so that users can work on different computers at the same time, instead of running between the different computers they want to use.

The LAN services we discuss in this chapter are programs that allow you to perform many operations between different computers using a LAN. These operations are:

Copy files from one computer to another. If you don't have a LAN, you can only copy your files with tape. Then go to another computer and reread the tape.

Log on to another computer from a terminal on the local computer. If there is no LAN, you usually have to go to which computer's terminal to log on.

Execute the command on another computer and observe the results locally. Similarly, if you do not have a LAN, you can only go to another computer to execute commands.

Accessing files on a remote computer means that we can use the disks on the other computer instead of copying the files to the local disk.

11.2 LAN Services

In this section, we understand that there are two different sets of services that let us use basic LAN functionality. These services are:

ARPA Service

Berkeley Service

ARPA service was first defined by Defense advaced (DARPA) in the early 60 's. These services become a standard for connecting many different kinds of computers through a single LAN. We are going to discuss the ARPA service with Telnet, and FTP.

DARPA employs Berkeley College's Bolt,baranek and Newman to develop these services. In the middle of the 70, Berkekey University began using the new UNIX operating system. They eventually developed a more robust service between computers running UNIX operating systems. These services are now called Berkeley Services. We will introduce Berkeley services such as Rcp,rlogin and Remsh in this chapter.

11.3 hostname Command

Syntax：

Hostname report your computer's name on the network

Example：

$ hostname

Fred

$

$ more/etc/hosts

192.1.2.1 Fred.

192.1.2.2 Barney

192.1.2.3 Wilma

192.1.2.4 Betty

Your computer has a host name. This host name is used to identify your system on the LAN. To view your host name, you can use the hostname command.

$ hostname

Fred

If you want to communicate with other computers on your LAN, you must know its hostname. You can ask your system administrator about the names of other computers. If you have a user account on the host you want to work on, you can also log in to check the host name yourself.

Note: To use any LAN service, you must be a valid user of the remote host.

You can also find the host name in the file hosts. However, if your LAN is large (for example, hundreds of hosts), this file will include hundreds of host names.