Firewalls and NAT

It all about what you do with an IP packet, generally using its TCP or UDP port number.

Extended reading references for NAT

• RFC 2663: IP Network Address Translator (NAT) Terminology and Considerations
• RFC 3022: Traditional IP Network Address Translator (Traditional NAT)
• NAT (Wikipedia)
• PAT (Wikipedia)
• How NAT Works from Cisco
• Description of NAT and how it impacts your online experience from Microsoft

Extended reading references for Firewall

• Firewall (Wikipedia)
• How Firewalls work
• Cisco PIX Firewall Software Configuration Guides
• iptables for oteen.cs.unca.edu