3.3 – High Availability and Disaster Recovery

Question 1

• Some servers are active, others are on standby- If an active server fails, the passive server takes its place

Answer 1

Load balancing

Question 2

UPS

Answer 2

• Uninterruptible Power Supply - Short-term backup power- Blackouts, brownouts, surges

Question 3

• Load Balancing / Fail Over (LBFO)- Aggregate bandwidth, redundant paths- Becomes more important in the virtual world
  Multiple network adapters - Looks like a single adapter - Integrate with switches
  NICs talk to each other- Usually multicast instead of broadcast - Fails over when a NIC doesn’t respond

Answer 3

NIC teaming

Question 4

Measure of how well a computer network can respond to connectivity and performance demands that are placed upon it

Answer 4

Network Availability

Question 5

• Provide multiple power outlets - Usually in a rack
• Often include monitoring and control - Manage power capacity- Enable or disable individual outlets

Answer 5

Power distribution units (PDUs)

Question 6

no hardware
no data
no people

Answer 6

cold site

Question 7

exact replica
duplicate
stocked with hardware

Answer 7

hot site

Question 8

just enough to get going
in between cold and hot
hardware but no data

Answer 8

warm site

Question 9

no separate facility
online management
data needs to move but not hardware

Answer 9

cloud site

Question 10

Two devices are installed and configured - Only one operates at a time
If one device fails, the other takes over- Constant communication between the pair
Configuration and real-time session information is constantly synchronized

Answer 10

Active-passive

Question 11

• You bought two devices- Use both at the same time
• More complex to design and operate- Data can flow in many different directions - A challenge to manage the flows- Monitoring and controlling data requires
  a very good understanding of the underlying infrastructure

Answer 11

Active-active

Question 12

• Your computer is configured with a single
  default gateway- We need a way to provide availability if the
  default gateway fails

Answer 12

FHRP (First Hop Redundancy Protocol)

Question 13

• The default router isn’t real- Devices use a virtual IP for the default gateway- If a router disappears, another one takes its place - Data continues to flow

Answer 13

VRRP (Virtual Router Redundancy Protocol)

Question 14

• Get up and running quickly- Get back to a particular service level

Answer 14

Recovery time objective (RTO)

Question 15

Mean time to repair (MTTR)

Answer 15

• Time required to fix the issue

Question 16

• Predict the time between outages

Answer 16

Mean time between failures (MTBF)

Question 16

• Predict the time between outages

Answer 16

Mean time between failures (MTBF)