Why implement a first-hop redundancy protocol?

First-hop redundancy protocols (FHRPs) like HSRP, VRRP, and GLBP are implemented to protect against default gateway failure. In a typical network, end devices are configured with a single default gateway IP address. If this gateway router fails, devices lose connectivity to other networks. FHRPs create a virtual default gateway IP address shared by two or more physical routers. If the active router fails, a standby router automatically takes over the virtual gateway IP, ensuring continuous connectivity without requiring changes to end-device configurations. Implementing FHRPs does not primarily allow multiple switches to operate as a single logical unit (that's more for technologies like VSS or stacking), provide load sharing for a multilink segment (that's for EtherChannel or link aggregation), or prevent network loops (that's Spanning Tree Protocol's role).