Networking Beginner

What is Firewall?

A network security system that monitors and controls incoming and outgoing traffic based on predetermined rules.

Firewalls act as gatekeepers between trusted internal networks and untrusted external networks. They filter traffic based on IP addresses, ports, protocols, and application data.

Types include packet filtering, stateful inspection, proxy, and next-generation firewalls (NGFW). Linux uses iptables or nftables. Common tools include UFW (Ubuntu) and firewalld (RHEL/CentOS).

Related Terms

An intermediary server that forwards requests between clients and destination servers, providing caching, filtering, or anonymity.

Network Topology

The physical or logical arrangement of nodes and connections in a computer network, such as star, mesh, ring, or bus configurations.

The seven-layer Open Systems Interconnection model that standardizes network communication functions from physical transmission to application protocols.

ARP (Address Resolution Protocol)

A protocol that maps IP addresses to physical MAC addresses on a local network segment.

HTTPS Everywhere

The practice of securing all web traffic with TLS encryption, ensuring data integrity and privacy between browsers and servers.

A network communication method that sends data to multiple recipients simultaneously without duplicating packets for each recipient.

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