What Does Hot Standby Router Protocol (HSRP) Mean?
Hot Standby Router Protocol (HSRP) is a redundancy routing protocol that establishes default fault tolerance and a framework for primary network gateway failover. HSRP is designed for multiaccess or broadcast local area networks (LAN) and supports non-disruptive Internet Protocol traffic inaccessibility.
HSRP is defined as RFC 2281.
Techopedia Explains Hot Standby Router Protocol (HSRP)
HSRP features include:
- Consistent IP routing protocol sets
- Works in a bridging environment
- Automatically self-updates when media access control (MAC) addresses are modified
- High-priority HSRPs are virtual (or active) routers with predefined gateway IP addresses
- HSRP groups or standby groups are HSRP router sets coordinated as illusory single active routers
- HSRP group routers have universal IP and MAC addresses.
- The virtual IP address for an HSRP group is the primary IP address LAN subnet and differs from other allocated interface addresses.
HSRP and active routers transmit messages on a periodic basis upon completion of protocol election. When an HSRP router fails or becomes an active router, the next standby router is selected to handle packet-forwarding duties. The active router then accepts and forwards traffic to the group’s virtual MAC address. When the active router leaves the LAN state, packet forwarding ends.