7.5.2 Methods used to improve the resilience of digital environments + 7.5.3 The benefits and drawbacks of methods used to improve the resilience of digital environments

Question 1

Fill The Blank:

Data ……………………… is where the same data is stored in multiple locations, and while it can be accidental, is often on purpose for ……………….. purposes to allow for data recovery.

Answer 1

Redundancy, Backup

Question 2

Fill The Blank:

Another advantage of data …………………….. is that it provides a mechanism for improving the …………………. of the data because it can be …………………… across multiple sites

Answer 2

Redundancy, Compared

Question 3

Explain:

Briefly, 2 disadvantages of data redundancy

Answer 3

• Data redundancy can cause data inconsistency if it is stored in multiple locations but the data does not match
• Risk of data corruption due to the transfer and/or storage of data between locations/systems
• Additional costs required for the storage of the data

Question 4

Explain:

Hardware redundancy

Answer 4

Consists of one or more additional compelte hardware systems (eg: additonal servers that can be used in case of failure)

Question 5

Explain:

Briefly, 3 types of redundancy

Answer 5

• Dynamic - Where only one system is working at a time and in case of failure an additional system is started so that the business processes can continue with minimum disruption
• Static - Where systems run in parallel, all carrying out the same processes - results are continually compared to check accuracy where in case of mismatches a predefined algorithm decides the best outcome
• Hybrid - Combination of dynamic and static hardware redundancy

These can be applied to both hardware and software redundancy

Question 6

Explain:

Disadvantages of hardware redundancy

Answer 6

• Means a more complicated system
• Additional costs for the components involved
• Redundant systems also have to be updated, upgraded and maintained alongside the main systems (otherwise it will become unreliable and less resilient)

Question 7

Explain:

Software redundancy

Answer 7

Where there is additional software that can carry out the same tasks as the current software being used

Question 8

Explain:

Back-up systems

Answer 8

• Not just backing up data but whole system (OS, software, configs)
• If incident occurs, business can restore system to a position prior to the incident

Question 9

State:

3 types of disaster recovery sites

Answer 9

• Hot site
• Cold site
• Warm site

Question 10

Explain:

Hot site

Answer 10

• Usually in a different location and runs in parallel to the normal system
• Replicate primary system and are usually maintained by third party (at a cost)
• Because they run in parallel they allow prompt restoration of functionality incase of an incident
• Because these sites have a backup of data, they allow immediate access to up-to-date data without having to source the location of any other data backups
• Can be in the cloud
• ‘A fully functioning, up-to-date replica in respect to equipment and data’

Question 11

Explain:

Cold site

Answer 11

• Cheapest option as it does not involve all facilities needed for hot site
• Only usually used when critical disaster occurs
• Only a form of data center so incase of an incident technical expertise will be required to install and configure the computer equipment so that the business can continue to function
• ‘Only have data and none of the equipment for the business environment’

Question 12

Explain:

Warm site

Answer 12

• Combination of a hot and cold site
• Digital equipment is made readily available but data must be restored onto the system
• Cost wise is between hot and cold sites
• ‘Contains basic equipment used in the business environment but does not include any data’

Question 13

State:

4 types of backups

Answer 13

• Full backup
• Incremental backup
• Differential backup
• Mirror backup

Question 14

Explain:

Full backup

Answer 14

• Backup of every file and folder in a system
• More time consuming and requires sufficient space for all of the data
• Faster when restoring lost data
• More robust and reliable than alternatives
• Only suitable if there is large changes to data on a regular basis

Question 15

Explain:

Incremental backup

Answer 15

• After creating full backup, only backup data that has changed since last backup
• Use less storage than full backups but use additional resources/compute to compare states of backups/data
• More time consuming to restore data from an incremental backup than full backup because it has to analyse the data within the backup to establish the timestamp for when data changed - several incremental backups may be required to restore data

Question 16

Explain:

Differential backup

Answer 16

• Data initially does full backup
• Then will only backup the data that has changed since last full backup
• Easier to recover data as only requires full backup and most recent differential backup

Question 17

Explain:

Mirror backup

Answer 17

• It is only a backup of the data, but entire system (OS, applications, configs)
• If hard drive fails, new HDD can be installed and mirror backup taken from the failed drive and can be restored onto new hard drive
• Faster than other backup types and create a ‘clean’ copy without old or outdated files and folders

Question 18

State:

4 ways that device hardening can be done

Answer 18

4 of;
* Disabling unused network ports
* Strict password management and file permissions
* Using multi-factor authentication using hardware tokens as well as passwords on networks
* Updating computer systems with security patches as they become available
* Removing all non-essential services and programs
* Setting time limits on access - can be frustrating for the user to be locked out after a short period of time because they have eg: answered a phone call

Question 19

Fill The Blank:

Device ……………………. is the methodss or processes used to eradicate any means of attack

Answer 19

Hardening

Question 20

Fill The Blank:

Careful ……………. has to take place when implementing device hardening - the implications to workflow and productivity must be considered as well as the protential for reducing the …………. surface areas of the system

Answer 20

Planning, Attack