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for HSRP such as authentication, tracking, or advertisement interval,
then first configure these parameters before enabling HSRP.
• HSRP creates a virtual MAC address for the master router based on a
standard prefix, with the last octet equal to the group ID. When a
backup router takes over as the master, it continues to forward traffic
addressed to this virtual MAC address. However, the backup router
cannot reply to ICMP pings sent to addresses associated with the
virtual group because the IP address owner is off line.
Virtual Router Priority –
• The router with the highest priority is elected as the master virtual
router. The router with the next highest priority is elected as the
standby router. The standby router will become the master router if the
current master fails. When the original master router recovers, it will
become the active master router again if the configured priorities have
not been changed.
• If two or more routers are configured with the same HSRP priority, the
router with the higher IP address is elected as the new master router if
the current master fails.
• The priority setting takes precedence over authentication. In other
words, if a router with a higher priority than any other router comes on
line, but is not configured with an authentication string, or is
configured with the wrong string, it will still take over as the active
master.
• The HSRP priority can change dynamically depending on the
availability of a tracked interface.
Preempting the Master –
• If preempt is enabled, and this router has a priority higher than the
current acting master, it will take over as the new master. If preempt is
not enabled, this router will only take over if it has the highest priority
in the group and the current master stops sending hello messages or