ABSTRACT
Today, the Internet serves over 1.01 billion hosts, around 1 billion websites and over 14.7 billion webpages live on the Internet, 49.5 billion webpages are indexed by Google, over 1 yottabyte (1024 bytes) of data resides on the Internet, over 40% of the world’s population uses the Internet (i.e., over 2.93 billion users), over 1.2 billion domain names are in use, over 200 billion e-mails are sent per day, and over 259 of 263 countries, colonies or territories, and disputed territories in the world provide access. It is projected that by 2020, over 60% (5 billion) of the planet will be connected by the Internet. UNIX has a special place in the world of networking in general and internetworking in particular because most of the networking protocols were initially implemented on UNIX platforms. Also, server processes running on UNIX-based computers provide most of the Internet services.
11.2 COMPUTER NETWORKS AND INTERNETWORKS When two or more computer hardware resources (computers, printers, scanners, plotters, etc.) are connected, they form a computer network. A hardware resource on a network or an internetwork is usually referred to as a host. Figure 11.1 (a) shows a schematic diagram of a network with six hosts, H1-H6.
