Network Layer (Layer 3)

  • Responsible for moving messages from one node to another until destination is reached
  • Maps logical addresses to physical addresses
    • Address Resolution Protocol (ARP)
  • IP adds own network layer header to segment or datagram
    • Entire network layer message is called a packet
  • IP addresses are used to identify hosts
  • IP relies on several routing protocols
    • Help find the best route for a packet to take
    • Examples: ICMP, ARP
  • Divides large packets into small packets
    • Fragmentation
  • Communicates between the transport layer and the data link layer

Computer Science Networking OSI Model