Hot Standby Router Protocol (HSRP)

Hot Standby Router Protocol, or HSRP, is a redundancy protocol developed by Cisco for IP networks. Multiple routers or Layer 3 switches form an HSRP group and provide end devices with a virtual IP address that serves as their default gateway. One device operates as the Active Router and forwards network traffic, while a Standby Router remains available for failover. If the active router becomes unavailable, the standby device automatically takes over its role while the virtual IP address remains accessible to end devices. This improves default gateway availability and reduces the risk of a single point of failure. HSRP is commonly used in enterprise networks and high-availability network infrastructures that require redundant gateway connections and rapid failover.