Cisco Systems 6500 manual 112

Chapter 2 Commands for the Catalyst 6500 Series SSL Services Module

standby timers

The standby timers command configures the time between standby hello packets and the time before other routers declare the active or standby router to be down. Routers or access servers on which timer values are not configured can learn timer values from the active or standby router. The timers configured on the active router always override any other timer settings. All routers in a Hot Standby group should use the same timer values. Normally, holdtime is greater than or equal to three times the value of hellotime. The range of values for holdtime force the holdtime to be greater than the hellotime. If the timer values are specified in milliseconds, the holdtime is required to be at least three times the hellotime value and not less than 50 milliseconds.

Some HSRP state flapping can occasionally occur if the holdtime is set to less than 250 milliseconds, and the processor is busy. It is recommended that holdtime values less than 250 milliseconds be used. Setting the process-max-timecommand to a suitable value may also help with flapping.

The value of the standby timer will not be learned through HSRP hellos if it is less than 1 second.

When group number 0 is used, no group number is written to NVRAM, providing backward compatibility.

Examples	This example sets, for group number 1 on Ethernet interface 0, the time between hello packets to 5
	seconds, and the time after which a router is considered to be down to 15 seconds:
	interface ethernet 0
	standby	1	ip
	standby	1	timers 5 15

This example sets, for the hot router interface that is located at 172.19.10.1 on Ethernet interface 0, the time between hello packets to 300 milliseconds, and the time after which a router is considered to be down to 900 milliseconds:

interface ethernet 0 standby ip 172.19.10.1

standby timers msec 300 msec 900

This example sets, for the hot router interface that is located at 172.18.10.1 on Ethernet interface 0, the time between hello packets to 15 milliseconds, and the time after which a router is considered to be down to 50 milliseconds. Note that the holdtime is three times larger than the hellotime because the minimum holdtime value in milliseconds is 50.

interface ethernet 0 standby ip 172.18.10.1 standby timers msec 15 msec 50

	Catalyst 6500 Series Switch SSL Services Module Command Reference
2-112	OL-9105-01