- Virtual IP address
A virtual IP address (VIP or VIPA) is an
IP address that is not connected to a specific computer or network interface card (NIC) on a computer. Incoming packets are sent to the VIP address, but all packets travel through real 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. [ [http://www.webopedia.com/TERM/v/virtual_IP_address.htm What is virtual IP address? - A Word Definition From the Webopedia Computer Dictionary ] ]
Example
A particular service is served by a collection of application servers. A virtual IP address is created so that applications using this service may direct their requests to that address without specifying the particular server to use. A load balancer such as a Citrix NetScaler serves this IP and redirects traffic using a hash or round robin algorithm to the backend servers. In case of a server failure, the configuration can be modified or automatically set so that traffic no longer goes to the failing server. From the user's perspective, uptime is maintained.
ee also
*
Virtual LAN
*IPMP Solaris virtual IP implementation for fault-tolerance and load balancingReferences
Wikimedia Foundation. 2010.