virtual IP address is an IP address

IP address

An Internet Protocol address is a numerical label assigned to each device participating in a computer network that uses the Internet Protocol for communication. An IP address serves two principal functions: host or network interface identification and location addressing...

 that is not connected to a specific computer or network interface card

Network card

A network interface controller is a computer hardware component that connects a computer to a computer network....

 (NIC) on a computer. Incoming packets are sent to the VIP address, but they are redirected to physical network interfaces.

VIPs are mostly used for connection redundancy; a VIP address may still be available if a computer or NIC fails, because an alternative computer or NIC replies to connections.

See also

• Virtual LAN
  Virtual LAN
  A virtual local area network, virtual LAN or VLAN, is a group of hosts with a common set of requirements that communicate as if they were attached to the same broadcast domain, regardless of their physical location...
  
  
• CARP
  Common Address Redundancy Protocol
  The Common Address Redundancy Protocol or CARP is a protocol which allows multiple hosts on the same local network to share a set of IP addresses. Its primary purpose is to provide failover redundancy, especially when used with firewalls and routers. In some configurations CARP can also provide...
  
  
• IPMP
  IPMP
  The IP network multipathing or IPMP is a facility provided by Solaris to provide fault-tolerance and load spreading for network interface cards . With IPMP, two or more NICs are dedicated for each network to which the host connects. Each interface is assigned a static "test" IP address, which is...
  
   Solaris virtual IP implementation for fault-tolerance and load balancing