Common Address Redundancy Protocol (CARP) for Unix
Description
UCARP allows a couple of hosts to share common virtual IP addresses in order
to provide automatic failover. It is a portable userland implementation of the
secure and patent-free Common Address Redundancy Protocol (CARP, OpenBSD's
alternative to the patents-bloated VRRP).
Strong points of the CARP protocol are: very low overhead, cryptographically
signed messages, interoperability between different operating systems and no
need for any dedicated extra network link between redundant hosts.