3.3 High Availability and Disaster Recovery

Question 1

In Load Balancing how are requests spread among devices on the network?

Answer 1

Client requests are spread from one active device to the next active device in an Active/Active system, or in the account of failover are sent from active device to passive device in a Active/Passive system.

Question 2

Explain the three First Hop Redundancy Protocols (FHRP).

Answer 2

Hot Standby Router Protocol (HSRP):
Cisco proprietary
Routers running HSRP create a virtual router with a virtual MAC address

Gateway Load Balancing Protocol (GLBP):
Cisco proprietary

Virtual Router Redundancy Protocol (VRRP):
Standards based protocol

Question 3

What is Mean Time Between Failure (MTBF)?

Answer 3

MTBF measures the reliability of a system or component.

Question 4

What is Mean Time to Repair/Recovery (MTTR)?

Answer 4

How long, on average, will it take to repair a component that fails.
Time to recovery includes time for problem diagnosis and repair.

Question 5

What is Recovery Time Objective (RTO)?

Answer 5

How long will it take for the system to be functional.

Question 6

What is Recovery Point Objective (RPO)?

Answer 6

At what point (percentage) is the system considered functional.