Secrets in This Chapter
Understanding IP Addresses
Getting IP Addresses for Your Network
Using Supernets or CIDR
Learning about IPv6
Routing TCP/IP Packets
Understanding the Domain Name System (DNS)
Performing Client/Server Communications with TCP/IP
Learning How xinetd Works
Understanding the xinetd Configuration Files
Starting Standalone Servers
Configuring Networks at Boot Time
UNIX and networking go hand in hand; TCP/IP (Transmission Control Protocol/ Internet Protocol) networking is practically synonymous with UNIX. As a UNIX clone, Linux includes extensive built-in networking capabilities. In particular, Linux supports TCP/IP networking over several physical interfaces, such as Ethernet cards, serial ports, and parallel ports.
Typically, you use an Ethernet network for your local area network (LAN)—at your office or even your home (if you happen to have several systems at home). TCP/IP networking over the serial port enables you to connect to other networks by dialing out over a modem. Linux supports both Serial Line Internet Protocol (SLIP) and Point-to-Point Protocol (PPP).
This chapter focuses on Linux’s support for Ethernet and TCP/IP. The chapter starts with a discussion of networking in general and TCP/IP in particular, then it covers the physical setup of an Ethernet LAN, including information about specific brands of Ethernet cards. Finally, the chapter describes how to set up a TCP/IP network on a Linux system.
Although much of this applies to TCP/IP over the serial line, this chapter does not dwell on the specific details of dial-up networking; that topic is the focus of Chapter 13. That chapter also describes how to connect to the Internet using cable modem and DSL as well as how to configure a wireless Ethernet LAN in Red Hat Linux.
Laptops often use PCMCIA cards (also called PC cards) for networking. Appendix F describes the PC cards that Linux supports.