A virtual IP address eliminates a host's dependency upon individual network interfaces.
Incoming packets are sent to the system's VIP address, but all packets travel through the real network interfaces.
Previously, if an interface failed, any connections to that interface were lost. With VIPA on your system and routing protocols within the network providing automatic reroute, recovery from failures occurs without disruption to the existing user connections that are using the virtual interface as long packets can arrive through another physical interface. Systems running VIPA are more highly available because adapter outages no longer affect active connections. Because multiple physical adapters carry the system IP traffic, overall load is not concentrated on a single adapter and associated subnet.
VIPA is one of the new protocols supported by Solaris 10:
* Berkeley Internet Name Domain (BIND9)
* Solaris Stream Control Transmission Protocol software
* Session Initiation Protocol (SIP)
* Open Shortest Path First (OSPFv2) and Border Gateway Protocol 4 (BGP-4) routing protocols
* Virtual IP source address selection (VIPA)