Which Cisco-proprietary protocol provides immediate, transparent, automatic traffic recovery when edge devices or access circuits fail?

HSRP (Hot Standby Router Protocol) is a Cisco-proprietary first-hop redundancy protocol that provides high network availability by enabling a group of routers to work together to present a single virtual IP address and MAC address to end devices. If the active router fails, a standby router automatically takes over, ensuring immediate and transparent traffic recovery without any disruption to the end-user. FHRP (First Hop Redundancy Protocol) is a general term for protocols that provide default gateway redundancy, not a specific protocol itself. VRRP (Virtual Router Redundancy Protocol) is an open-standard FHRP, but the question specifically asks for a Cisco-proprietary protocol. SLB (Server Load Balancing) is a technique for distributing network traffic across multiple servers, unrelated to first-hop redundancy.