IP Addresses vs MAC Addresses

• MAC address


  A unique identifier hard-coded into a network adapter or interface card
• MAC address


  • Meant to be unique worldwide
  • Stored in device memory
  • Can be spoofed for security reasons
• IP address


  An address assigned to a device connected to a network running the Internet Protocol
• IP address


  • Needs to be unique only on the local network
  • Provides information about the device's geographical location
• MAC address


  Physical address, permanent and tied to the network adapter
• IP address


  Logical address, comes and goes based on network connection
• Delivering a data packet

  1. Router uses IP address to route to general location

  2. MAC address is used to deliver to the specific device
• Both MAC and IP addresses are needed because they operate at different network layers
• MAC addresses are switched out at each hop in the routing process, IP addresses generally do not change
• Protocols like ARP and NDP are used to convert between IP and MAC addresses
• IP addresses identify a connection between a device and a network, not a specific device