D-Link UNIFIED WIRED & WIRELESS ACCESS SYSTEM DWS-3000 - Manual (Page 87)

CLI Examples 87
14
Virtual Router Redundancy Protocol
When an end station is statically configured with the address of the router that will handle its
routed traffic, a single point of failure is introduced into the network. If the router goes down,
the end station is unable to communicate. Since static configuration is a convenient way to
assign router addresses, Virtual Router Redundancy Protocol (VRRP) was developed to
provide a backup mechanism.
VRRP eliminates the single point of failure associated with static default routes by enabling a
backup router to take over from a “master” router without affecting the end stations using the
route. The end stations will use a “virtual” IP address that will be recognized by the backup
router if the master router fails. Participating routers use an election protocol to determine
which router is the master router at any given time. A given port may appear as more than one
virtual router to the network, also, more than one port on a Unified Switch may be configured
as a virtual router. Either a physical port or a routed VLAN may participate.
CLI Examples
This example shows how to configure the Unified Switch to support VRRP. Router 1 will be
the default master router for the virtual route, and Router 2 will be the backup router.