ccna certification free ebooks

ccna certification free ebooks.Chapter 2 IP AddressesIP addresses are the foundation on which the Internet works. An IP address is used to uniquely identify the interface of a computer or network device on a network. It is a logical address, and efficient IP address planning ensures that the network operates efficiently. There are two major types of IP addresses in use today, IPv4 and IPv6. As IPv4 addresses are about to be exhausted, the future of the network will be dominated by IPv6 addresses. This chapter introduces the structure, types, subnetting, and VLSM of IPv4 addresses, as well as IPv6 features, the structure and types of IPv6 addresses, IPv6NDP, and IPv6 transition technologies. This chapter is one of the most basic knowledge points that should be mastered for learning network technology.2.1 IPv4 Addresses2.1.1 IPv4 Address StructureIPv4 addresses are 32-bit binary numbers in length and are usually represented as dotted decimal numbers, with each decimal number consisting of 8 binary digits. When the Internet was originally designed to facilitate addressing and hierarchical network construction, IP addresses consisted of a network address and a host address, and the network portion of the IPv4 address must be identical for all devices on the same network, while the host portion of the IPv4 address must be unique. When you configure an IPv4 address, you also configure a subnet mask. Like IPv4 addresses, the length of the subnet mask is a 32-bit binary number. The network address is represented as the result of a logical sum operation between the subnet mask and the IPv4 address, and the host address is represented as the IPv4 address minus the network address. The IP address structure is shown in Figure 2.1.Main State Blood ScriptIPv4 address 192 168 . 10 I11000000 10101000 00001010 00001010Subnet Mask 255 255 255 255 1 ------------------011111111 11111111 11111111 00000000