Tools

http://ports.my-addr.com/tcp_port-udp_port-application-and-description.php
http://www.subnetonline.com/pages/subnet-calculators/ipv4-to-ipv6-converter.php

pf

http://pfsense.org

iptables

http://serverfault.com/questions/244036/iptables-rules-to-allow-l2tp-ipsec-vpn-behind-firewall

Custom applications

iOS: Understanding Notifications

Links

http://www.linuxhomenetworking.com/wiki/index.php/Quick_HOWTO_:_Ch14_:_Linux_Firewalls_Using_iptables

http://netfilter.org/ (iptables)

www.linuxhomenetworking.com – Quick_HOWTO_:_Ch14_:_Linux_Firewalls_Using_iptables

http://lindesk.com/2007/04/internet-connection-sharing-using-iptables/

Linux Advanced Routing & Traffic Control HOWTO – Classifying packets with filters

L7-filter – Application Layer Packet Classifier for Linux

wiki-Deep_packet_inspection

Intel AMT Manageability Ports

Speedguide – Port reference