document updated 13 years ago, on Mar 4, 2011

wikipedia
5 WAYS TO IMPLEMENT IT (see bottom of page)
specific pieces of software that implement the "virtual IP address" functionality

NAT can do it
FAKE — via ARP spoofing
IP tunneling
heartbeat, vrrpd, carp, and keepalived
NIC teaming on Linux
larger writeups

@sun.com
@sanog.org (the first couple of slides seem like crap, but it gets better halfway through)
@proj.sunet.se

random links that I still have to process

virtual IP
Linux-VS.org's use of a Virtual IP Address to fail-over