Full form: Hot Standby Router Protocol
Also known as: Hot Standby Router Protocol
Quick Definition
A Cisco proprietary FHRP that provides a virtual IP gateway shared by an active and standby router.
HSRP is a Cisco-proprietary First Hop Redundancy Protocol (FHRP). Two (or more) routers share a virtual IP address and virtual MAC address. One router is elected Active and handles all traffic to the virtual IP; another is Standby, ready to take over if the Active fails. Hosts configure the virtual IP as their default gateway so they are unaffected when a physical router fails. The Active router is elected based on highest priority (default 100), then highest real IP address as a tiebreaker.
interface GigabitEthernet0/0 standby 1 ip 192.168.1.254 standby 1 priority 110 standby 1 preempt
HSRP preempt is not enabled by default. Without preempt, even if the original Active router recovers with a higher priority, it will not automatically reclaim the Active role — the current Active keeps it.
The IP address of the router a host sends packets to when the destination is on a different subnet.
A category of protocols that provide a virtual gateway IP shared across multiple routers for redundancy.
An open-standard FHRP where routers elect a Master that owns the virtual IP and responds to ARP requests.
A Cisco proprietary FHRP that provides redundancy and load balancing using multiple virtual MACs.
HSRP is a Cisco-proprietary First Hop Redundancy Protocol (FHRP). Two (or more) routers share a virtual IP address and virtual MAC address. One router is elected Active and handles all traffic to the virtual IP; another is Standby, ready to take over if the Active fails. Hosts configure the virtual IP as their default gateway so they are unaffected when a physical router fails. The Active router is elected based on highest priority (default 100), then highest real IP address as a tiebreaker.
HSRP preempt is not enabled by default. Without preempt, even if the original Active router recovers with a higher priority, it will not automatically reclaim the Active role — the current Active keeps it.
HSRP falls under the Routing domain of the 200-301 exam. Understanding it in context with related terms like fhrp and vrrp is essential for answering scenario-based questions correctly.