CCNA 2.2 IP Addressing

• An IP address consists of 32 bits of information (divide into four octets)
• The 32 bit IP address is a structured or hierarchical address
• Network address uniquely identifies each network
• Node/Host address uniquely identifies each device on a network
• Three classes of networks:

• In Class A network address the first bit of the first byte must always be off (0-127)
• In Class B network address the first bit of the first byte must always be on but the second bit is always off (128-191)
• In Class C network address the first two bit of the first byte must always be on (192-223)
• Class D network is used for multicast address (224-239)
• Class E network is used for scientific purpose (240-255)
• Reserved IP addresses:

• Private IP address is used for security measure and saving IP address space
• Reserved private IP address space: