Specifications

Application View Cisco HSRP Application
Device Management Page 151 Cisco Router
the active router. In the priority range of 0 to 255,
0 is the lowest priority and 255 is the highest
priority.
If two (or more) routers in a group have the same
priority, the one with the highest IP address of the
interface is the active router. When the active
router fails to send a Hello message within a
configurable period of time, the standby router
with the highest priority becomes the active
router.
A router with highest priority will only attempt to
overthrow a lower priority active router if it is
configured to preempt. But, if there is more than
one router which is not active, the highest priority
non-active router becomes the standby router.
Preempt
A value of True indicates that the current router
should attempt to overthrow a lower priority
active router and attempt to become the active
router. A value of False indicates the router will
become the active router only if there is no such
router (or if an active router fails).
Preempt Delay
The time difference between a router power up
and the time it can actually start preempting the
currently active router.
When a router first comes up, it doesn't have a
complete routing table. If it's configured to
preempt, then it will become the Active router, but
it will not be able to provide adequate routing
services. The solution to this is to allow for a
configurable delay before the router actually
preempts the currently active router.
Use Configured Timers
HSRP routers learn a group's Hellotime or
Holdtime from hello messages.
The Hellotime is used to determine the frequency
of generating hello messages when this router
becomes the active or standby router. The
Holdtime is the interval between the receipt of a
Hello message and the presumption that the
sending router has failed.
If this field is True, the Configured Hello Time
(Page 152) and Configured Hold Time (Page 152)
will be used. If it is False, these values are
learned.