IP Addressing & MAC Addressing (OCR GCSE Computer Science): Revision Notes
📚 Revision Notes
IP Addressing & MAC Addressing
IP Addressing and MAC Addressing are two methods used to identify devices on a network. Both serve different purposes but are essential for communication within and between networks.
Overview of Key Differences
IP Address
- Dynamic and can change depending on the network you're connected to.
- Used for global identification across networks (e.g., the internet).
MAC Address
- Static and unique to each device's hardware.
- Used within local networks to deliver data to the right device.
IP Addressing
- IP (Internet Protocol) Address: A unique numerical identifier assigned to each device connected to a network. It helps route data from one device to another over the internet.
- Use: IP addresses allow devices to locate and communicate with each other on a network, such as a website server or a computer in a local network.
Types of IP Addresses
IPv4
- The most widely used IP address format.
- Consists of 4 groups of numbers separated by periods (dots).
- Each group (called an octet) ranges from 0 to 255.
- Limited to about 4.3 billion addresses.
IPv6
- A newer version designed to replace IPv4 due to the shortage of IPv4 addresses.
- Consists of 8 groups of hexadecimal numbers separated by colons.
- Provides 340 undecillion addresses, solving the address limitation problem of IPv4.
MAC Addressing
- MAC (Media Access Control) Address: A unique hardware identifier assigned to a network interface card (NIC) by the manufacturer.
- Use: MAC addresses are used within a local network to ensure that data is sent to the correct physical device. While IP addresses change based on the network, a MAC address remains constant for each device.
Format of a MAC Address
- A MAC address consists of 6 pairs of hexadecimal numbers (0-9, A-F), separated by colons or hyphens.
- The first half identifies the manufacturer (Organizationally Unique Identifier), while the second half identifies the specific device (Network Interface Controller identifier).
infoNote
Key Points to Remember:
- IPv4 uses a 32-bit address format, while IPv6 uses a 128-bit address, providing vastly more addresses.
- MAC addresses are hardware-based and unique to each network device, ensuring proper device identification on a local network.
- IP addresses can be reassigned and changed, but MAC addresses remain the same for the device's lifetime.