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).
