IPv4 Addresses — TechKnowSurge

About this video

IPv4 addresses are 32-bit binary values that computers process as sequences of ones and zeros, but are expressed in human-readable form as four decimal numbers separated by dots, each ranging from 0 to 255. This dotted-decimal notation divides the 32 bits into four 8-bit groups called octets, and the full address space spans from 0.0.0.0 to 255.255.255.255, yielding more than 4.2 billion possible addresses. Every IPv4 address contains two logical sections: a network portion that identifies which network the address belongs to, and a host portion that identifies a specific device within that network. Subnet masks determine where the boundary between the network and host portions falls. Represented in the same dotted-decimal format as an IP address, a subnet mask uses binary ones to designate network bits and binary zeros to designate host bits, always assigning network bits from left to right. Because of this binary structure, valid subnet mask values within any octet are limited to a specific set of numbers: 0, 128, 192, 224, 240, 248, 252, 254, and 255. A Class C address, for example, assigns the first three octets to the network and the last octet to hosts, corresponding to a subnet mask of 255.255.255.0. Within any IPv4 network, three address categories serve distinct roles. The network address is the first address in the range and identifies the network itself rather than any individual device. The broadcast address is the last address in the range and is used to send traffic to all devices on that network simultaneously, defining what is known as a broadcast domain. All addresses between those two boundaries are usable host addresses that can be assigned to individual machines, with the first usable address immediately following the network address and the last usable address immediately preceding the broadcast address.

What you'll learn

Describe the structure of an IPv4 address, including binary-to-decimal conversion, octet notation, and the valid address range
Explain how subnet masks define the network and host portions of an IPv4 address and identify network, host, and broadcast address types within a classful address range

What's covered

IPv4 Addresses Overview

Address Structure
- 32 Bits Total
  - 4.2 Billion Addresses
- Four Octets
  - Dotted Decimal Notation
  - Range 0 to 255
Network vs Host Side
- Classful Addressing
  - Class C Three Octets Network
  - Last Octet Host Side
- Subnet Masks
  - Ones Define Network Bits
  - Zeros Define Host Bits
  - Valid Mask Values
IPv4 Address Types
- Network Address
  - First Address in Range
- Host Addresses
  - First and Last Usable
- Broadcast Address
  - Last Address in Range
  - Sent to All Devices

Aligned to

CompTIA Network+

1.7 Given a scenario, use appropriate IPv4 network addressing.

Cisco CCNA

1.6 Configure and verify IPv4 addressing and subnetting.

Cisco CCST Networking

2.2 Identify IPv4 addresses and subnet formats.

CompTIA A+ Core 1

2.6 Compare and contrast common network configuration concepts.

Cisco CCST Cybersecurity

2.2 Explain how network addresses impact network security.

Key terms

IP Address: A numerical label assigned to each device connected to a network that uses the Internet Protocol.
Subnet Mask: A 32-bit number that divides an IP address into network and host portions.
Subnet: A logical subdivision of an IP network, used to organize and segment network traffic.
Octet: One of the four 8-bit sections of an IPv4 address, each separated by a dot in dotted decimal notation and representing a decimal value from 0 to 255. For example, in 192.168.1.1, the four octets are 192, 168, 1, and 1.
Network Address: The first address in an IP network range that identifies the network itself and cannot be assigned to a host. It is formed when all host bits are set to zero.
Broadcast Address: The last address in an IP subnet range, formed when all host bits are set to one, used to send a single packet to every device on that network simultaneously.
Host Address: An IP address assigned to a specific device on a network; the host portion is neither all zeros nor all ones.

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