Chapter 6

Chapter 6

1. Networks share information and use various methods to direct the manner in which information flows.

   • A host is any device that sends and receives information on the network.

2. When data is sent over a computer network, it is broken up into small chunks called packets.

   • Bandwidth is measured in bits per secon
     • The amount of time it takes data to travel from source to destination is called latency.

3. Working with 128-bit numbers is difficult, so the IPv6 address notation represents the 128 bits as 32 hexadecimal values.

   • The global prefix, also called a site prefix, is the first three blocks of the address and is assigned to an organization by an Internet names registry. The subnet ID includes the fourth block of the address, and the interface ID includes the last four blocks of the address. The network administrator controls both the subnet and interface ID.
     • As an example, if a host has an IPv6 address 3ffe:6a88:85a3:08d3:1319:8a2e:0370:7344, the global prefix address is 3ffe:6a88:85a3, the subnet ID address is 08d3, and the interface ID address is 1319:8a2e:0370:7344.
       • Replace one group of consecutive zeroes by a double colon.

4. Internet Control Message Protocol (ICMP) is used by devices on a network to send control and error messages to computers and servers.

   • Ping is commonly used to test connections between computers.
     • The ipconfig command is another useful command-line utility used to verify that a NIC has a valid IP address.
       • Ping works by sending an ICMP echo request to a destination computer or other network device.
         • You can also use ping to find the IP address of a host when that host’s name is known.

5. An Internet appliance is also called a Net appliance, a smart appliance, or an information appliance. Examples of Internet appliance devices include televisions, game consoles, Blu-ray players, and streaming media players. The device is designed for the specific function and has built-in hardware for Internet connectivity. The Internet connection is either wired or wireless. Internet appliances include a CPU and RAM that support email, web surfing, gaming, as well as video streaming and social networking, as shown in the figure.