ABSTRACT
This chapter describes networks and internetworks and explains why they are used. It discusses the Transmission Control Protocol/Internet Protocol (TCP/IP) suite, IP addresses, protocol ports, and Internet services and applications. The core of internetworking software is based on the TCP/IP protocol suite. This suite includes, among several other protocols, the well known TCP and IP protocols for transportation and routing of application data. The key to routing in the Internet is 32-bit IP addresses (in IPv4) and 128-bit addresses (in IPv6). The chapter also discusses various network software tools for electronic communication, remote login, file transfer, remote command execution, tracing a route in the Internet, and status reporting. It explains what the client-server software model is and how it works, and describes the Secure Shell and other secure commands. The chapter covers the following commands and primitives: finger, ftp, ip, host, nslookup, ping, scp, sftp, ssh, talk, telnet, and traceroute.
