CIDR subnets and notation

Simple connection status and firewall concept

Understanding how network connections are tracked and how firewalls make decisions about traffic is a foundational skill for any cybersecurity professional. In the previous activities, you explored how TCP handshakes work, how to capture and filter t...

Read the Linux VM routing table

**Theoretical Recap** A routing table is a data structure stored in the kernel of an operating system that determines how network packets are forwarded from one network interface to another. Every Linux machine — whether a workstation, server, or vir...

Simplified routing and routing tables

Routing is one of the most fundamental mechanisms in computer networking. It is the process by which data packets travel from one network to another until they reach their destination. Understanding how routing works is essential for anyone entering ...

Adjust the subnetwork for a need

**Theoretical Recap** A subnet (subnetwork) is a logical subdivision of an IP network. The core tool for defining subnets is CIDR (Classless Inter-Domain Routing) notation, written as an IP address followed by a prefix length (e.g., 192.168.1.0/24). ...

Calculate the /24 and /26 address range

**Theoretical Recap** An IP address in IPv4 is a 32-bit number divided into two parts: the network portion and the host portion. CIDR notation (Classless Inter-Domain Routing) expresses this split using a suffix like /24 or /26, which indicates how m...