Implement gateway redundancy technologies

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Questions derived from the 642-812 – Building Converged Cisco Multilayer Switched Networks (BCMSN) Cisco Self Test Software Practice Test.

 

Objective: Implement gateway redundancy technologies
SubObjective: Configure HSRP, VRRP and GLBP

 

Item Number: 642-812.4.2.3
Single Answer, Multiple Choice

 

Which of the following statements best describes the result of issuing the command standby 44 timers 3 1 on an HSRP router?

 

 

  1. The holdtime will be set to a value of 3, and the hellotime will be set to a value of 1.
  2. The status of the standby router will be displayed as “unknown expired.”
  3. The role of active router will be passed repeatedly from one router to another.
  4. The router will be configured to reassume the role of active router in the event that the router fails and is subsequently restarted.

 

Answer:
C. The role of active router will be passed repeatedly from one router to another.

 

Tutorial:
When the command standby 44 timers 3 1 is issued on a Hot Standby Routing Protocol (HSRP) router, the role of active router will be passed repeatedly from one router to another; this behavior occurs when the timers are set incorrectly. The syntax for the standby timers command is standbygroup-numbertimershellotimeholdtime. The hellotime variable is the number of seconds between hello messages and is set to a value of 3 by default. The holdtime variable is the number of seconds that the HSRP standby router will wait before assuming that the active router is down; if the standby router believes the active router to be down, it will assume the role of active router. The holdtime is set to a value of 10 by default. The holdtime should be set to a value at least three times the value of the hellotime. Otherwise, the active router might not be able to respond before the standby router assumes that the active router is down and becomes the new active router. Because the command standby 44 timers 3 1 sets the hellotime to a value of 3 and the holdtime to a value of 1, the role of active router will be passed from one standby router to the next. To set the holdtime to a value of 3 and the hellotime to a value of 1, the command standby 44 timers 1 3 should be issued. To reset the timer values to their default values, the command no standby group-number timers should be issued.

 

The status of the standby router will be displayed as “unknown expired” if a Physical layer problem exists. The “unknown expired” status can also be displayed if only one HSRP router is configured for the subnet.

 

To configure an HSRP router to reassume the role of active router in the event that the router fails and is subsequently restarted, the command standby group-number preempt should be issued. When the HSRP active router fails or is shut down, the standby router assumes the role of active router. By default, when the original HSRP active router is restarted, it does not take the role of active router away from the original standby router, even if the original active router has a higher priority value. The command standby group-number preempt changes this default behavior.

 

Reference:
http://www.cisco.com/univercd/cc/td/doc/product/lan/cat3750/12111ax/3750scg/swhsrp.htm#1044255

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