Network Security

Discover why using a VPN does not guarantee total anonymity and how browser fingerprinting or account logins can still reveal an identity to websites.

Almost all web traffic rides on ports 80 and 443. Learn what each carries, why HTTPS on 443 matters, and how redirects and HSTS enforce encryption.

NAT lets many devices share one public IP, and is often mistaken for a firewall. Learn what NAT does, the protection it offers, and why it is not security.

Banner grabbing reads the identifying text a service returns to learn its software and version. Learn how it aids recon and why hiding banners is weak defense.

Network enumeration is the recon phase of mapping hosts, services, and structure. Learn what attackers gather and why defenders enumerate too.

Wi-Fi security has evolved from broken WEP to modern WPA3. Learn how the protocols differ, why the old ones fail, and what to use to secure a wireless network.

A DDoS attack overwhelms a target with traffic from many sources to knock it offline. Learn the main types — volumetric, protocol, and application-layer.

A handful of ports carry most network traffic. Learn the common ports and their services, why the mapping matters, and how attackers use it in recon.

Nmap is the standard tool for network discovery and port scanning. Learn what it does, its core scan types, and why it is essential for defenders too.

Port scanning probes a host to find which services are listening. Learn how scans work, the common scan types, and why it is step one of recon — and defense.

A proxy server sits between clients and destinations, forwarding requests on their behalf. Learn forward vs reverse proxies and their roles in security.

A VPN creates an encrypted tunnel across an untrusted network. Learn what a VPN does and does not protect, and why it is not the privacy cure-all it is sold as.

A firewall filters network traffic against rules, allowing or blocking it. Learn the types of firewall, what they can and cannot do, and where they fit.

DNS turns names into addresses and underpins the whole internet — which makes it a rich target. Learn how DNS works and the main ways it is attacked.

The OSI model breaks networking into seven layers, a shared language for describing where things happen. Learn the layers and how they map to real attacks.

The TCP/IP model is where many network attacks live. Learn the four layers, what each adds, and why understanding them is the basis of network security.

A network tap copies traffic on a link for monitoring without disrupting it. Learn how taps differ from SPAN ports and why they give reliable visibility.

A bastion host is a hardened gateway that is the single controlled entry point to a private network. Learn how it shrinks exposure and concentrates monitoring.

Egress filtering controls what leaves your network, not just what enters. Learn why outbound control catches data theft and C2, and how to apply it.

Network traffic analysis inspects flows and packets to find threats and anomalies. Learn what it reveals, how it catches attacks, and why metadata matters.

A rogue access point is an unauthorized Wi-Fi network used to trick devices into connecting. Learn the evil-twin attack and how to detect rogue APs.

DHCP spoofing plants a rogue DHCP server to feed victims malicious network settings. Learn how it enables man-in-the-middle and how DHCP snooping stops it.

Zero trust networking removes implicit trust from the network, verifying every access. Learn how it replaces the perimeter model and what it takes to adopt.

SSH is the standard for secure remote access — and a constant attack target. Learn how SSH works and the key steps to harden it: keys, no root, and config.

A honeypot is a decoy system built to attract and study attackers. Learn how honeypots detect intrusions with almost no false positives, and their trade-offs.

A SYN flood exhausts a server by opening half-finished TCP connections it must hold. Learn how the handshake is abused and why SYN cookies defeat it.

IP spoofing forges the source address of packets to hide their origin or impersonate a host. Learn how it works and why egress filtering helps.

Network Access Control decides which devices may join a network and what they can reach. Learn how NAC enforces posture and its role in zero trust.

Port knocking hides a service until a secret sequence of connection attempts opens it. Learn how it works, its value as obscurity, and its real limitations.

A bind shell opens a listening port on a compromised host for the attacker to connect to. Learn how it differs from a reverse shell and why firewalls limit it.

A reverse shell has a compromised host connect back to the attacker, bypassing inbound firewalls. Learn how it works, why it is favored, and how to detect it.

A Wi-Fi deauth attack forces devices off a network by forging management frames. Learn how it works, what it enables, and why WPA3 finally protects against it.

A WAF filters HTTP traffic to block common web attacks before they reach the app. Learn what a WAF catches, its limits, and why it is a layer, not a fix.

DNS over HTTPS encrypts DNS queries so local observers cannot see or tamper with them. Learn what DoH protects, the trade-offs, and how it differs from DNSSEC.

DNSSEC adds cryptographic signatures to DNS so answers can be verified as authentic. Learn what it protects against, what it does not, and why it matters.

Surviving a DDoS attack means absorbing or filtering flood traffic before it overwhelms you. Learn the core techniques and why scale is the main defense.

Packet sniffing captures network traffic for analysis. Learn how sniffing works, what Wireshark reveals, and why it matters to attackers and defenders.

An IDS detects suspicious network activity; an IPS blocks it. Learn how they differ, signature vs anomaly detection, and where they fit in a defense stack.

Network segmentation divides a network into zones so a breach cannot spread freely. Learn how it limits lateral movement and how microsegmentation extends it.

Stateless firewalls judge each packet alone; stateful ones track connections. Learn how they differ, their trade-offs, and why stateful became the default.

A man-in-the-middle attacker sits between two parties, reading or altering traffic. Learn the common techniques and why end-to-end encryption defeats them.

ARP spoofing lets an attacker on your local network intercept traffic by forging address mappings. Learn how it enables man-in-the-middle and how to detect it.

DNS spoofing feeds a resolver forged answers so users are sent to malicious servers. Learn how cache poisoning works and why DNSSEC and encryption help.

TLS is the protocol that secures almost all internet traffic. Learn what it provides — encryption, integrity, authentication — and how it fits together.

Once inside, attackers move laterally using the network’s own protocols and trust. Learn the network techniques and the controls that make movement visible.

IPsec secures traffic at the network layer, encrypting and authenticating IP packets. Learn its modes and protocols, and where it fits versus TLS.

Certificate pinning ties an app to a specific certificate or key, rejecting all others. Learn how it blocks fraudulent certificates and the risk of pinning.

Mutual TLS authenticates both sides of a connection, not just the server. Learn how mTLS works, where it shines, and its real operational cost.

BGP hijacking reroutes internet traffic by announcing false routes on the protocol that connects networks. Learn how it works and why RPKI is the emerging fix.

VLAN hopping lets an attacker reach segments they should be isolated from. Learn the switch-spoofing and double-tagging techniques and how to prevent them.

The TLS handshake sets up a secure channel before any data flows. Learn what happens in each step, how keys are agreed, and how TLS 1.3 made it faster.