Configuring Hsrp Authentication And Timers - Cisco Catalyst 3750 Software Configuration Manual

Configuring HSRP
Use the no standby [group-number] priority priority [preempt [delay delay]] and no standby
[group-number] [priority priority] preempt [delay delay] interface configuration commands to restore
default priority, preempt, and delay values.
Use the no standby [group-number] track type number [interface-priority] interface configuration
command to remove the tracking.
This example activates a port, sets an IP address and a priority of 120 (higher than the default value),
and waits for 300 seconds (5 minutes) before attempting to become the active router:
Switch# configure terminal
Switch(config)# interface gigabitethernet1/0/1
Switch(config-if)# no switchport
Switch(config-if)# standby ip 172.19.108.254
Switch(config-if)# standby priority 120 preempt delay 300
Switch(config-if)# end
Switch#

Configuring HSRP Authentication and Timers

You can optionally configure an HSRP authentication string or change the hello-time interval and
holdtime.
When configuring these attributes, follow these guidelines:
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•
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Beginning in privileged EXEC mode, use one or more of these steps to configure HSRP authentication
and timers on an interface:
Command
Step 1
configure terminal
Step 2
interface interface-id
Step 3 standby [group-number] authentication string
Catalyst 3750 Metro Switch Software Configuration Guide
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The authentication string is sent unencrypted in all HSRP messages. You must configure the same
authentication string on all routers and access servers on a cable to ensure interoperation.
Authentication mismatch prevents a device from learning the designated Hot Standby IP address and
timer values from other routers configured with HSRP.
Routers or access servers on which standby timer values are not configured can learn timer values
from the active or standby router. The timers configured on an active router always override any
other timer settings.
All routers in a Hot Standby group should use the same timer values. Normally, the holdtime is
greater than or equal to 3 times the hellotime.
Purpose
Enter global configuration mode.
Enter interface configuration mode, and enter the HSRP
interface on which you want to set authentication.
(Optional) authentication string—Enter a string to be carried in
all HSRP messages. The authentication string can be up to eight
characters in length; the default string is cisco.
(Optional) group-number—The group number to which the
command applies.
Chapter 29 Configuring HSRP
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