http://www.zytrax.com/books/dns/ch9/rr.html
http://www.alliedtelesis.com/media/datasheets/howto/config_redundancy_sd_a.pdf
http://www.cisco.com/en/US/docs/security/asa/asa71/asdm51/selected_procedures/asdm_lb.pdf
http://www.isaserver.org/tutorials/Configuring_Network_Load_Balancing.html
http://www.howtoforge.com/loadbalanced_mysql_cluster_debian
http://www.juniper.net/techpubs/software/junos/junos70/swconfig70-policy/html/policy-actions-config11.html
http://docs.sun.com/source/819-0215/loadb.html
Open source:
http://www.haproxy.org/
https://www.inlab.de/articles/free-and-open-source-load-balancing-software-and-projects.html
http://www.zenloadbalancer.com/
http://louwrentius.com/overview-of-open-source-load-balancers.html
http://freeloadbalancer.com/
http://kemptechnologies.com/solutions/linux-solutions/
http://www.infoworld.com/article/2918974/servers/nginx-open-source-server-gets-tcp-load-balancing.html
http://linuxpoison.blogspot.com/2008/09/opensource-load-balancing-software.html