◆ファイヤーウォール

Little Snitch
http://www.obdev.at/products/littlesnitch/index.html

Hands Off!
http://www.metakine.com/products/handsoff/

WaterRoof
http://www.hanynet.com/waterroof/index.html

NoobProof
http://www.hanynet.com/noobproof/index.html

TCPBlock
http://tcpblock.wordpress.com

ipfw
http://www.freebsd.org/doc/en/books/handbook/firewalls-ipfw.html
http://www.freebsd.org/doc/ja/books/handbook/firewalls.html

pf
http://www.openbsd.org/faq/pf/
http://ja.wikipedia.org/wiki/PF_(ファイアウォール)