# Chapter 6: Disaster Recovery

* Business Continuity Planning (BCP): continuation of business via alternative plans.
* Disaster Recovery (DR) is the set of processes used to reach the objectives of the Business Continuity Plan.
* Key security aspects CIA: Confidentiality, Integrity, Availability

## Pre-disaster process
Have a process in place to determine what is and is not a disaster, and when to invoke the plan.

## Setting objectives
* Recovery Point Objective (RPO): the point in time that you wish to recover to. What is acceptable: seconds before the disaster strikes, the night before, or the week before? The shorter the RPO, the more costs and complexity.
* Recovery Time Objective (RTO): time permitted to reach the RPO.

These should be driven by the business owners!

## Recovery strategies
- Have regular backups
- Warm standbys
- High-availability systems
- Fail-over scenario’s:
	- Use alternative systems (e.g. if VoIP crashes, use cellphones)
	- System Function Reassignment: repurposing noncritical systems to replace critical systems (e.g. use an acceptation-environment as a production environment; requires that the two environments be separated enough that a disaster affecting one will not affect the other).
	- Have a process for switching back

Test regularly!

**tot hier verwerkt**


## Understand Dependencies
Map them. Example: if you have an email server with an RTO of 1 hour, and yet the network on which it depends has an RTO of 3 hours, irrespective of how quickly the email server is up and running, it may not be resuming operation in any meaningful sense until 3 hours have elapsed.

## Develop Scenario’s
For testing your procedures and training staff.

A few broad categories of scenarios useful to consider:

* Hardware failure of mission-critical platform
* Loss of a data center
* Pandemic

## Pre-disaster process
Have a process in place to determine what is and is not a disaster, and when to invoke the plan.

One of the most effective routes is to have a list of named individuals or roles who are authorized to determine when the organization is in a disaster situation and that the plan needs to be executed.

The process for anyone who is not authorized to make this determination is to escalate to someone who can.

## Security Considerations
* Secure Data at Rest
* Secure Data in Transit
* Patching and configuration management on backup systems
* User access
* Physical security on secondary sites

