IP and MAC Addresses

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IP Address

An Internet Protocol (IP) address is a rational numerical address which is allocated to every single computer and computer device that is a member of a given Transmission Control Protocol / Internet Protocol (TCP/IP)-based network.

The IP address is the main element on which the networking architecture is made—no network occurs without it.  An IP address is a relevant address that is used to distinctly classify every node in the network.  Because IP addresses are relevant, they can be altered.  They are like addresses in a city because of the way the IP address provides the network node a location, so that it can connect with other nodes or networks—just like a mail is sent to friends.

Parts of an IP Address

The numbers in an IP address are broken down into 2 parts:

  • The network part indicates which networks the address pertains to
  • The host part identifies the specific location

An IP Address is the most essential element in the networking development which connects the various disparate parts of the World Wide Web into what we call the internet.  The IP address is a numeric address, which is specified for every single instance with regards to any computer communication network that makes use of the TCP/IP communication procedures.

Standards for IP Address

There are 2 standards for IP addresses:

  • IP Version 4 (IPv4) – composed of 4 sets of numbers from 0 to 255, divided by 3 dots. There are 28X4 probable IPv4 addresses.  There are 3 classes of IPv4 address sets that can be recorded through the Internet Network Information Center (InterNIC):
    • Class C – composed of 256 IP addresses (123.123.123.xxx, where xxx is from 0 to 255)
    • Class B – composed of 65,536 IP addresses (123.123.xxx.xxx)
    • Class A – composed of 16,777,216 IP addresses (123.xxx.xxx.xxx)
  • IP Version 6 (IPv6) – composed of 8 sets of 4 hexadecimal digits, divided by colons. There are 3.4 x 1038 probable IPv6 addresses.

Static vs. Dynamic IP Address

  • Static IP address – this will never vary, and can be considered a perpetual internet address.
  • Dynamic IP address – this is a provisional address that is allocated each time a computer or device connects to the internet.

MAC Address

The Media Access Control (MAC) address is a binary number used to specify particular computer network adapters.  These numbers, also known as hardware addresses or physical addresses, are either installed in the network hardware during the manufacturing process, or are saved in firmware, and intended to never be altered.

Some refer to them as Ethernet addresses, but Wi-Fi and Bluetooth networks also make use of MAC addressing.

Format of a MAC Address

Conventional MAC addresses are composed of 12-digit hexadecimal numbers and are usually written as follows:

  • MMM.SSS.SSS
  • MM-MM-MM-SS-SS-SS
  • MM:MM:MM:SS:SS:SS

They are 48 bits or 6 bytes.

Prefix refers to the first 6 digits or first 24 bits and is identified with the adapter manufacturer.  Each vendor registers and acquires MAC prefixes as allocated by the Institute of Electrical and Electronics Engineers (IEEE).  Vendors often obtain many prefix numbers identified with various products they create and sell.

The last 6 digits of a MAC address serve as an identification number for the specific device in question.  For devices made with the same vendor prefix, each is assigned with their own specific 24-bit number.  Hardware from different vendors may turn out to share the same device section of the address.

Some kinds of networks require 64-bit addresses like the Zigbee wireless home automation.

MAC vs. IP Address Relationship

TCP/IP networks use both MAC and IP addresses but for different purposes.

MAC Address IP Address
Fixed to the device’s hardware Can be altered depending on the device’s TCP/IP network configuration
Works at Layer 2 of the Open Systems Interconnection (OSI) Works at Layer 3 of the OSI