High Availability and Disaster Recovery Flashcards
If a network has five nines availability, how much downtime does it experience
per year?
a. 30 seconds
b. 5 minutes
c. 12 minutes
d. 26 minutes
Answer: b. Five nines availability means 99.999% uptime and translates into
about 5 minutes of downtime per year.
What mode of NIC redundancy has only one NIC active at a time?
a. Publisher-subscriber
b. Client-server
c. Active-passive
d. Active-subscriber
Answer: c. The active-passive design uses one NIC that is actually active and
able to pass traffic. The other NIC is in a passive (often called standby) state.
What performance optimization technology involves a network appliance that
can receive a copy of content stored elsewhere (for example, a video presentation located on a server at a corporate headquarters) and serves that content to
local clients, thus reducing the bandwidth burden on an IP WAN?
a. Content engine
b. Load balancer
c. LACP
d. CARP
Answer: a. A content engine permits the caching of key data to which clients
need low-latency access.
What type of backup solution is a point-in-time, read-only copy of data?
a. Differential
b. Incremental
c. Snapshot
d. Virtual
Answer: c. A snapshot is typically a complete point-in-time read-only copy of data.
What type of site provides a nearly identical level of service to the organization’s main site, with virtually no downtime?
a. Warm
b. Cold
c. Hot
d. Remote
Answer: c. A hot site is often the ultimate goal of a disaster recovery design. A
hot site would be able to provide full-service levels with virtually no downtime
after a disaster occurs.
What capability of routing protocols allows them to help you use the bandwidth that you might have available in a multipathing design?
a. ECMP
b. Distance vector
c. Link state
d. Dual stack
Answer: a. Equal-cost multipathing (ECMP) enables routing protocols to
distribute traffic among different available paths in the network. This is very
advantageous, especially compared to classic Layer 2 designs that feature STP,
which blocks redundant paths in order to prevent loops.
In order to measure high availability (HA), you need to know the average
amount of time that passes between hardware component failures. What is this
called?
a. MTTR
b. RPO
c. RTO
d. MTBF
Answer: d. The mean time between failure (MTBF) is the average amount of
time that passes between hardware component failures, excluding time spent
repairing components or waiting for repairs.
You are tasked with locating a backup facility for your organization to use in
the event of a disaster. You have a slim budget, and the facility needs to include
electricity, bathrooms, and space. Which type of recovery site suits your
requirements?
a. Hot site
b. Cold site
c. Warm site
d. Cloud site
Answer: b. A cold site is the weakest of the recovery sites but also the least
costly. (However, although a cold site may be the least costly when you’re
planning for disaster, after a disaster occurs, equipment purchased for a cold
site might be expensive or difficult to obtain.) Electricity, bathrooms, and space
are about the only facilities a cold site contract provides.
Which of the following statements are true regarding backups? (Select three.)
a. The difference between incremental and differential backups is that a
differential backup includes all data that has changed since the last incremental backup.
b. A differential backup includes all data that has changed since the last full
backup.
c. An incremental backup is incomplete for full recovery without a full
backup and all incremental backups since the last full backup.
d. A full backup is the safest and most comprehensive way to ensure data
availability, but it can be time-consuming and costly.
Answer: b, c, d. The difference between incremental and differential backups is that differential backups include all data that has changed since the full
backup. Therefore, answer a is the only false statement.
