Firewalls

Firewalls

1. A firewall protects computers and networks by preventing undesirable traffic from entering internal networks.

2. Types of firewalls

   • Packet filtering
     • Prevents or allows access based on IP or MAC addresses
   • Application filtering
     • Prevents or allows access by specific application types based on port numbers
   • URL filtering
     • Prevents or allows access to websites based on specific URLs or keywords
   • Stateful packet inspection (SPI)
     • Unsolicited packets are blocked unless permitted specifically.