HP 6125XLG R2306-HP 6125XLG Blade Switch Layer 3 - IP Services Configuration G - Page 25

Configuring IP addressing The IP addresses in this chapter refer to IPv4 addresses unless otherwise specified. This chapter describes IP addressing basic and manual IP address assignment for interfaces. Dynamic IP address assignment (BOOTP and DHCP) and PPP address negotiation are beyond the scope of this chapter. Overview This section describes the IP addressing basics. IP addressing uses a 32-bit address to identify each host on an IPv4 network. To make addresses easier to read, they are written in dotted decimal notation, each address being four octets in length. For example, address 00001010000000010000000100000001 in binary is written as 10.1.1.1. IP address classes Each IP address breaks down into the following sections: • Net ID-Identifies a network. The first several bits of a net ID, known as the class field or class bits, identify the class of the IP address. • Host ID-Identifies a host on a network. IP addresses are divided into five classes, as shown in Figure 7. The shaded areas represent the address class. The first three classes are most commonly used. Figure 7 IP address classes Table 1 IP address classes and ranges Class Address range A 0.0.0.0 to 127.255.255.255 B 128.0.0.0 to 191.255.255.255 Remarks The IP address 0.0.0.0 is used by a host at startup for temporary communication. This address is never a valid destination address. Addresses starting with 127 are reserved for loopback test. Packets destined to these addresses are processed locally as input packets rather than sent to the link. N/A 16