IPv4, or Internet Protocol version 4, is one of the core protocols of standards-based internetworking methods in the Internet and other packet-switched networks. This guide will provide a simple yet thorough understanding of IPv4, addressing, and subnetting, targeting students and learners new to the concept.
What is IPv4?
IPv4 is the fourth version of the Internet Protocol (IP). It was the first version of the protocol to be widely deployed and forms the backbone of most Internet communications. IPv4 addresses are unique identifiers assigned to devices connected to a network, allowing them to communicate with each other
IPv4 Addressing
An IPv4 address is a 32-bit number, typically represented in decimal format as four 8-bit fields separated by periods (e.g., 192.168.1.1). Each field is a byte (8 bits), ranging from 0 to 255.
| Decimal Address | Binary Address |
|---|---|
| 192.168.1.1 | 11000000.10101000.00000001.00000001 |
Classes of IPv4 Addresses
IPv4 addresses are divided into five classes (A, B, C, D, and E), each designed for different types of networks.
| Class | Range (First Octet) | Default Subnet Mask | Purpose |
|---|---|---|---|
| A | 0-127 | 255.0.0.0 | Large networks |
| B | 128-191 | 255.255.0.0 | Medium-sized networks |
| C | 192-223 | 255.255.255.0 | Small networks |
| D | 224-239 | N/A | Multicast groups |
| E | 240-255 | N/A | Experimental, reserved for future use |
Subnetting in IPv4
Subnetting is a technique used to divide a network into smaller, more manageable segments. It helps improve network performance and security.
| Subnet Address | Subnet Mask | Host Range | Broadcast Address |
|---|---|---|---|
| 192.168.1.0 | 255.255.255.0 | 192.168.1.1 – 192.168.1.254 | 192.168.1.255 |
| 192.168.1.0/26 | 255.255.255.192 | 192.168.1.1 – 192.168.1.62 | 192.168.1.63 |
| 192.168.1.64/26 | 255.255.255.192 | 192.168.1.65 – 192.168.1.126 | 192.168.1.127 |
Key Concepts in IPv4
- Network Address Translation (NAT): Allows multiple devices on a local network to share a single public IP address.
- DHCP (Dynamic Host Configuration Protocol): Automatically assigns IP addresses to devices on a network.
- CIDR (Classless Inter-Domain Routing): A method for allocating IP addresses and routing that replaces the older system based on classes A, B, and C.
Summary
IPv4 is a foundational technology for modern networking, enabling devices to communicate through unique addressing. Understanding the basics of IPv4 addressing and subnetting is crucial for students and anyone interested in networking.
| Feature | Description |
|---|---|
| Address Length | 32 bits |
| Address Representation | Dotted decimal notation (e.g., 192.168.1.1) |
| Address Classes | A, B, C, D, E |
| Subnetting | Divides a network into smaller sub-networks |
| Key Protocols | NAT, DHCP, CIDR |