UNIX System Management: Configuring the Arpa/berkeley Service

By completing this chapter, you will be able to do the following things:

Learn about commonly used arpa-http://www.aliyun.com/zixun/aggregation/33795.html ">berkeley services."

Understanding the Super Daemon: the inetd feature.

Learn about the process of starting the Ftp/telnet service in inetd.

Learn about inetd configuration files.

Start or stop the Network service at the command line.

Start or disallow some Internet service by configuring the inetd.conf file.

Allows or disables the use of a selected client for network services by configuring the Inetd.sec file.

Configure the passwd file to allow or disallow the use of network services by specified users.

Logs Arpa/berkeley Network SERVICE requests.

Use the/etc/hosts.equiv file to define trust relationships between hosts.

Use the ~/.rhosts file to define a user's trust relationship between hosts.

Overview of 1.Internet Services

Functional Description ARPA Berkeley

Terminal access

File transfer

remote command execution

E-mail

Internal process Communication

Network Information

Dynamic routing

Name Service

Time synchronization

Remote boot

Remote printing

Telnet

ftp

SMTP

Gated

NTP

BOOTP

Rlogin

rcp

Remsh, rexec

SendMail (using SMTP)

Sockets

Rwho,ruptime,finger

BIND

Printer (Rlpdaemon)

Client/server mode for the 2.internet service

A client uses a service server to provide a service

# rlogin Gary <-----------------> Rlogind

Internet services are based on client/server mode.

The client uses the services provided by the server. The keyword "client/server" is often used between systems rather than between processes, but one server is able to provide services because one service process is running, and on the other, a client can only run a client process to communicate with a process on the server.

A system that runs both a client process and a server process can be both a server and a client.

The example above illustrates a simple client/server relationship in which a user executes a rlogin command on node Roger to obtain a virtual terminal from the Gary node. The Rlogin program is a client-side process. The server is running the corresponding server-side process-rlogind, and then a network communication conversation thread is established between Rlogin and Rlogind.