IPv4 /26 Subnetting Explained: A Beginner-Friendly Guide

Subnetting is an important networking skill for IT students and people preparing for certifications such as the CCNA Subnetting is an important networking skill for IT students and people preparing for certifications such as the CCNA. It helps you understand how IP addresses are grouped into networks. In this tutorial, we'll work through an IPv4 /26 subnet example step by step. 1. What does /26 mean? The /26 is a CIDR prefix. It means that 26 of the 32 bits in an IPv4 address identify the network. The subnet mask for /26 is 255.255.255.192. Each /26 subnet contains 64 total IP addresses. Traditionally, two addresses are reserved for the network address and broadcast address, leaving 62 usable host addresses in a conventional IPv4 subnet. 2. Calculate the subnet size The interesting octet is the last one, where the subnet mask is 192. Subnet block size = 256 - 192 = 64. The subnet ranges are 192.168.1.0–192.168.1.63, 192.168.1.64–192.168.1.127, 192.168.1.128–192.168.1.191, and 192.168.1.192–192.168.1.255. 3. Work through an example Suppose a computer has IP address 192.168.1.70/26. Since 70 falls between 64 and 127, its network address is 192.168.1.64/26. Subnet mask: 255.255.255.192 Network address: 192.168.1.64 Broadcast address: 192.168.1.127 Usable host range: 192.168.1.65–192.168.1.126 Usable host addresses: 62 4. Test yourself A computer has the IP address 192.168.1.150/26. Which network address is correct? A. 192.168.1.0/26 B. 192.168.1.64/26 C. 192.168.1.128/26 D. 192.168.1.192/26 Answer: C — 192.168.1.128/26. The address 150 falls within the range 128–191. 5. Keep practising The easiest way to improve at subnetting is to practise identifying block sizes, network addresses, broadcast addresses, and usable host ranges. Explore my free IT certification study resources covering networking, cloud computing, and cybersecurity: https://github.com/pintocristofer9870-hub/free-it-certification-resources For additional IT certification preparation resources, visit https://examsteacher.com/. Keep practising, and try calculating the next subnet yourself before checking the answer.