Linux 2.4 Advanced Routing HOWTO website, http://www.linuxguruz.com/iptables/howto/2.4routing.html
Linux Advanced Routing & Traffic Control HOWTO website, http://lartc.org/
The Linux Networking Overview HOWTO website, http://www.tldp.org/HOWTO/Networking-Overview-HOWTO.html
The GNU Zebra Project website, http://www.zebra.org
The Quagga Routing Suite website, http://www.quagga.net
NextHop Technologies GateD website, http://www.gated.org
Multithreaded Routing Toolkit (MRT) website, http://www.mrtd.net
The Bird Internet Routing Daemon website, http://bird.network.cz
The Extensible Open Router Platform (XORP) website, http://www.xorp.org
The Zebra ISISd project website, http://isisd.sourceforge.net
IP infusion website, http://www.ipinfusion.com
MIT's Click Modular Router Project website, http://www.pdos.lcs.mit.edu/click
The Net-SNMP Home website, http://www.net-snmp.org/
The Linux-PAM (Pluggable Authentication Modules for Linux) Project website, http://www.kernel.org/pub/linux/libs/pam/