What is the difference between a MAC address and an IP address?

MAC (Media Access Control) address and IP (Internet Protocol) address are two distinct identifiers used in networking, each serving a specific purpose. Let's delve into the technical details of both:

  1. MAC Address (Layer 2 Address):
    • Physical Address: MAC address is also known as the hardware address or physical address. It operates at the data link layer (Layer 2) of the OSI model.
    • Uniqueness: Each network interface card (NIC) has a unique MAC address assigned by the manufacturer. It is a 48-bit address represented in hexadecimal format, typically displayed as six groups of two characters separated by colons or dashes (e.g., 00:1A:2B:3C:4D:5E).
    • Locally Administered Addresses: Some MAC addresses are designated as locally administered, meaning they can be set manually. However, the universally administered addresses are assigned by the manufacturer.
    • No Geographical Hierarchy: MAC addresses are assigned without any geographical hierarchy. They are primarily used for identifying devices on a local network segment.
  2. IP Address (Layer 3 Address):
    • Logical Address: IP address operates at the network layer (Layer 3) of the OSI model. It is a logical address assigned to devices to enable communication across different networks.
    • Hierarchical Structure: IP addresses have a hierarchical structure, consisting of network and host portions. There are two types of IP addresses: IPv4 and IPv6. IPv4 addresses are 32-bit long, often represented in dotted-decimal format (e.g., 192.168.1.1), while IPv6 addresses are 128-bit long (e.g., 2001:0db8:85a3:0000:0000:8a2e:0370:7334).
    • Dynamic Assignment: IP addresses can be dynamically assigned using DHCP (Dynamic Host Configuration Protocol) or configured statically. DHCP allows devices to obtain an IP address dynamically when they join a network.
    • Geographical Hierarchy: IP addresses can provide information about the geographical location of a device, especially with regional IP address allocations.

Key Differences:

  • Layer of Operation: MAC addresses operate at the data link layer (Layer 2), while IP addresses operate at the network layer (Layer 3).
  • Uniqueness: MAC addresses are globally unique, assigned by the device manufacturer, while IP addresses may be dynamically assigned and can be reused in different networks.
  • Address Length: MAC addresses are 48 bits long, and IP addresses can be either 32 bits (IPv4) or 128 bits (IPv6) long.
  • Scope: MAC addresses are primarily used for communication within a local network, whereas IP addresses enable communication across different networks.