IP (Internet Protocol)

• Operates at the network layer
  • Specifies where data should be delivered
  • Identifies the data's source and destination IP addresses
• Enables TCP/IP to internetwork to traverse:
  • More than one LAN segment
  • More than one type of network through router
• Unreliable, connectionless
  • Does not guarantee delivery of data
  • No session established before data is transmitted
  • Depends on TCP:
    • To ensure messages are put back together in proper order
    • To ensure each message reaches the correct application on receiving host

IP Packet

• The smallest unit used to describe data being sent over IP (aside from bytes)
• $2^{16}$ bytes
  • Not very large
• Consists of:
  • An IP header
    • The source and destination IP addresses
    • Other information related to the network
  • A payload
    • Data being sent over the network

IPv4 Packet

IPv6 Packet

Networking Computer Science TCP-IP