Firewall
A firewall is a network security system that monitors and controls incoming and outgoing traffic based on predetermined rules, acting as a barrier between a trusted internal network and untrusted external networks such as the internet.
21 resources across 3 libraries
Glossary Terms(11)
Zero Trust Architecture
Zero Trust Architecture is a security model built on the principle of "never trust, always verify" — no user, device, or network segment is trusted by default,…
Firewall
A firewall is a network security system that monitors and controls incoming and outgoing traffic based on predetermined rules, acting as a barrier between a tr…
Cloud Firewall
A cloud firewall is a network security service, delivered and managed by a cloud provider or third party, that filters inbound and outbound traffic to cloud re…
Squid Proxy
Squid is a mature, open-source caching and forwarding proxy server that supports HTTP, HTTPS, and FTP, commonly used to reduce bandwidth usage and control outb…
Palo Alto Networks
Palo Alto Networks is a cybersecurity company known for its next-generation firewall appliances and a broad security portfolio spanning network security, cloud…
Fortinet
Fortinet is a cybersecurity company best known for its FortiGate line of next-generation firewalls and its broader Security Fabric platform, which unifies netw…
Cisco Umbrella
Cisco Umbrella is a cloud-delivered security service that uses DNS-layer and secure web gateway filtering to block malicious domains, malware, and phishing sit…
Intrusion Prevention System (IPS)
An Intrusion Prevention System (IPS) is a network security tool that monitors traffic for malicious activity, like an Intrusion Detection System, but can autom…
Virtual Private Network (VPN)
A Virtual Private Network (VPN) creates an encrypted tunnel between a device and a remote network or server, protecting data in transit and allowing the device…
DDoS Attack
A Distributed Denial-of-Service (DDoS) attack is an attempt to overwhelm a server, service, or network with a flood of traffic from many compromised sources at…
PCI DSS
PCI DSS (Payment Card Industry Data Security Standard) is a set of security requirements created by major card brands that all organizations handling, processi…
Study Notes(1)
Interview Questions(9)
What is a Firewall?
A firewall is a network security system that monitors and controls incoming and outgoing traffic based on a defined set of rules, sitting between a trusted int…
What is Port Scanning?
Port scanning is the technique of systematically probing a target host’s TCP or UDP ports to discover which ones are open, closed, or filtered, revealing what…
What is Port Forwarding and How Does It Work?
Port forwarding is a router/NAT configuration that maps an incoming connection on a public IP address and port to a specific private IP address and port inside…
What is a DMZ Network?
A DMZ (demilitarized zone) is a physically or logically separated network segment that sits between an organization’s trusted internal network and the untruste…
What is OpenVPN?
OpenVPN is an open-source VPN protocol and software suite that builds an encrypted tunnel between a client and a server using TLS for key exchange and either O…
What is Network Segmentation?
Network segmentation is the practice of dividing a network into smaller, isolated segments — using VLANs, subnets, firewalls, or software-defined policies — so…
What is a Network Firewall Rule?
A network firewall rule is a single ordered instruction — matching criteria like source/destination IP, port, and protocol, plus an action of allow or deny — t…
Stateful vs Stateless Firewall: What is the Difference?
A stateful firewall tracks the full context of each active connection and automatically permits return traffic belonging to an already-approved session, while…
What is Deep Packet Inspection (DPI)?
Deep Packet Inspection (DPI) is a network filtering technique that examines the actual payload data of a packet, not just its header, so a firewall, router, or…