Virtual router redundancy protocol (VRRP) and the related Cisco proprietary hot standby router protocol (HSRP) provide a mechanism to deal with router failure without disrupting endpoints on the network. In essence, these protocols work by assigning a virtual IP address and MAC address for the routers. This address is given to endpoints as their default gateway. The two routers send periodic hello messages marked with a priority value between each other. The high-priority router assumes the virtual address, and traffic flows through it. If the primary router fails or its capabilities become degraded (such as if a WAN link fails), the secondary router takes over. This is a useful mechanism to protect endpoints from router failures, and works with IP Telephony endpoints.