US Patent 7933198 Virtual router failover dampening

A virtual router spans a number of physical routing devices. One of the physical routing devices is designated as master, and the other physical routing devices are designated as backups to the master. A failover protocol that includes both a non-dampened state and a dampened state can be implemented. According to the failover protocol, an attempt to designate one of the backups as master in place of the current master is permitted while the virtual router is in the non-dampened state, while such an attempt is suppressed while the virtual router is in the dampened state.