Computer networks are the backbone of modern communication, enabling devices to exchange data and connect to the Internet. To understand cybersecurity, it’s essential to first explore the fundamental components, protocols, and operations that make these networks function. In Networks & Attacks 101, we work on the essentials based off of Enterprise 101’s topology. Building the essential network infrastructure, deploying network-based attacks such as Man-in-the-Middle (MiTM), Denial of Service (DoS), Address Resolution and IP Spoofing. We then deploy defenses, such as the Suricata Intrusion Prevention System (IPS), pfSense Firewall, Active Directory Group Policy Objects (GPO), and File Integrity Monitoring (FIM).