Editing Virtual Router Redundancy Protocol (section)

{{Short description|Inter-router protocol that automatically assigns routers to hosts}}
{{Distinguish|Vehicular Reactive Routing protocol}}
The '''Virtual Router Redundancy Protocol''' ('''VRRP''') is a computer [[networking protocol]] that provides for automatic assignment of available  [[Internet Protocol]] (IP) routers to participating [[Host (network)|hosts]]. This increases the availability and reliability of [[routing]] paths via automatic [[default gateway]] selections on an IP [[subnetwork]].

The protocol achieves this by the creation of virtual routers, which are an abstract representation of multiple routers, i.e. primary/active and secondary/Standby [[router (computing)|router]]s, acting as a group. The virtual router is assigned to act as a default gateway of participating hosts, instead of a physical router. If the physical router that is routing packets on behalf of the virtual router fails, another physical router is selected to automatically replace it. The physical router that is forwarding [[Network_packet|packets]] at any given time is called the primary/active router.

VRRP provides information on the state of a router, not the routes processed and exchanged by that router. Each VRRP instance is limited, in scope, to a single subnet. It does not advertise IP routes beyond that subnet or affect the routing table in any way. VRRP can be used in [[Ethernet]], [[Multiprotocol Label Switching|MPLS]] and [[Token Ring]] networks with [[IPv4|Internet Protocol Version 4]] (IPv4), as well as [[IPv6]].