The Virtual Router Redundancy Protocol (VRRP) for IPv4 is defined in the IETF RFC 3768, Virtual Router Redundancy Protocol. VRRP describes a method of implementing a redundant IP interface shared between two or more routers on a common LAN segment, allowing a group of routers to function as one virtual router. When this IP interface is specified as a default gateway on hosts directly attached to this LAN, the routers sharing the IP interface prevent a single point of failure by limiting access to this gateway address. For more information about use of VRRP, see the 7210 SAS-Mxp, R6, R12, S, Sx, T Router Configuration Guide.