Top free Linux firewalls

http://www.mondaiji.com/blog/other/it/10175-the-hunt-for-the-ultimate-free-open-source-firewall-distro

Sophos UTM Home (50 IP address limit for free edition)

Untangle Free Edition

PFSense (FreeBSD based)

OPNSense (Fork of PFSense)

IPFire

Vyatta

Smoothwall                           

For AWS pfSense:
http://thepracticalsysadmin.com/setting-up-a-pfsense-nat-instance-in-aws/

US East (N. Virginia) – ami-11a58278

US West (Oregon) – ami-3430ab04

US West (N. California) – ami-0c417049

EU (Ireland) – ami-b69874c1

Asia Pacific (Singapore) – ami-9c1541ce

Asia Pacific (Tokyo) – ami-1f0e681e

Asia Pacific (Sydney) – ami-6fdf4055

South America (Brasil) – ami-cb13b5d6

Update 26/5/2016 - Commercial support for PFSense- 10Gb firewall:

Includes:

https://www.netgate.com/docs/pfsense/firewall/adding-rules-with-easyrule.html