High Availability

Question 1

What type protocol would you deploy if you wanted redundancy in your routers? Name two.

Answer 1

First Hop Redundancy Protocols:

1) Hot Standby Router Protocol (Cisco)
2) Virtual Router Redundancy Protocol

Question 2

Why isn’t HSRP cost efficient?

Answer 2

The standby router does nothing until it becomes the primary.

Question 3

List the 3 names and sizes of a HSRP virtual MAC address

Answer 3

1) Vendor ID - 24bits
2) HSRP ID - 16bits
3) HSRP group number - 8bits

Question 4

List the HSRP timers

Answer 4

1) Hello
2) Hold
3) Active
4) Standby

Question 5

What does the Hold Timer do and what is the default value?

Answer 5

The hold timer specifies the interval the standby router uses to determine if the active router is unavailable. The default value is 10 seconds.

Question 6

What does the Active Timer do?

Answer 6

monitors the state of the active router.

Question 7

The Hold Timer value sets the expiry time for what other timer?

Answer 7

The Active Timer

Question 8

What messages reset the the Active Timer and where are they received?

Answer 8

Hello messages. Standby Router

Question 9

How are standby routers monitored in HSRP?

Answer 9

by Standby Timers

Question 10

It is recommended to set the Hold Timer to a multiple of the Hello message frequency, of what amount?

Answer 10

x3

Question 11

What is a VRRP group?

Answer 11

a virtual router that represents a group of routers

Question 12

In VRRP using a virtual IP, the router with the highest priority is the what?

Answer 12

The Master router

Question 13

If HSRP uses hello messages to exchange state information, what does VRRP use?

Answer 13

VRRP messages!

Question 14

You want to be able to load-share across more than one virtual router, which First Hop Redundancy Protocol would you deploy?

Answer 14

VRRP