Linux Firewalls By Shane Lofgren

Definition from wikipedia.org: A firewall is a security device which is configured to permit, deny or proxy data connections set and configured by the organization's security policy. Firewalls can either be hardware and/or software based. A firewall's basic task is to control traffic between computer networks with different zones of trust. Typical examples are the Internet which is a zone with no trust and an internal network which is a zone with high trust.

Firewall Types ● Software – Included in AV suites – ZoneAlarm – firestarter ● Hardware – Purchase (Linksys, Netgear, Cisco) – Linux

Linux Firewalls ● Install any distribution and make a firewall ● Install a firewall distribution ● Use a firewall live CD

Linux Live CD Firewalls ● Smoothwall ● IPcop ● Redwall ● m0n0wall ● pfSense

PfSense Features ● Easy Setup wizard ● SSL Web interface ● Captive portal – forces an HTTP client on a network to see a special web page (usually for authentication purposes) before surfing the Internet normally. ● IPsec VPN ● Squid proxy ● Nmap network scanner

Minimum Hardware Requirements ● 133 MHz processor ● 128 MB RAM ● 64 MB RAM if only used as a basic firewall ● 2 GB Hard Drive if installed ● Two network cards ● CDROM ● Floppy drive or USB drive if ran in Live CD ● Keyboard for initial setup

Setting up pfSense ● Boot from CD ● Text based wizard detects interfaces ● Configure interfaces and IP addresses ● Access firewall with web browser to finish configuration

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