HSRP / FHRP

HSRP (Hot Standby Routing Protocol) – Cisco proprietary protocol used for first hop redundancy.

FHRP (First Hop Redundancy Protocol) – open protocol for same goal: first hop redundancy.

2 switches required for implementation. HSRP using virtual MAC and virtual IP to process packets. (And yes, in our case it is working on VLAN interfaces).

Sample configuration

SW1 configuration:

interface Vlan10
  description SuperVLAN for HSRP
  no shutdown
  no ip redirects
  ip address 10.10.10.2/24
  hsrp version 2
  hsrp 1
    preempt
    priority 50
    timers msec 250 msec 750
    ip 10.10.10.1

Sw2 configuration:

interface Vlan10
  description SuperVLAN for HSRP
  no shutdown
  no ip redirects
  ip address 10.10.10.3/24
  hsrp version 2
  hsrp 1
    preempt
    priority 50
    timers msec 250 msec 750
    ip 10.10.10.1