2 IPv4Internet Protocol addressing version 4 (IPv4) is the basis of Internet.Every connected host has a four octet address expressed in decimal:AAA.BBB.CCC.DDDFor example: (Google)A host can send a packet to an IP address and it will be delivered to the correct destination.
3 CLASSFUL ADDRESSINGUnder IPv4 addressing scheme (classful addressing), the class of the network may be A, B or C. The class effects how the four number IP address is intrepreted. For all classes, the last byte is limited between: 1 – 254: reserved for network address- 255: reserved for broadcast address
5 CLASS A (large network): the first byte identifies the network and the last 3 bytes represent an address range for hosts on the network.Byte 1: 1 – 126Byte 2 and 3: 0 – 255No. of hosts (max): 16,646,144CLASS B (medium network): the first two bytes identify the network and the last 2 bytes represent an address for hosts on the network.Byte 1: 128 – 191No. of hosts (max): 65,024CLASS C (small network): the first three bytes identify network and the last byte represent an address for hosts on the network.Byte 1: 192 – 223No. of hosts (max): 254 hostsCLASS D: Byte 1: 224 – 239CLASS E: Byte 1: 240 – 255
6 Broadcast Address: broadcast address is intended to go to every host on the network. (host address bytes are replaced with 255 (all ones)Example: Class B network with a network address of would have a broadcast address of
7 Network Address: is formed by replacing all host bytes with 0. Example: Class B IP address of , has network address ofNetwork Mask (netmask): a host must know if a received packet relates to the network to which the host is a member. Membership of a network is determined using netmask defined on every network host.netmask = all network bits set to 1, all hosts bitsset to 0Example: Class A = , Class B =
8 5 Different Classes of IP Address CLASS AtoCLASS BtoCLASS CtoCLASS DtoCLASS Eto
9 PRIVATE IP ADDRESS (are not used anywhere on public internet, reserved for private LANs) Network ClassNetwork NumbersNetwork MaskNo. of NetworksNo. of Hosts per NetworkCLASS A12616,646,144CLASS Bto16,38365,024CLASS Cto2,097,151254LOOPBACK (localhost)to-