text: Chapter 2
  DEPARTMENT OF DEFENSE INFORMATION NETWORK
  OPERATIONS
  2-5. The Department of Defense information network is the set of information capabilities and associated
  processes for collecting, processing, storing, disseminating, and managing information on demand to
  warfighters, policy makers, and support personnel, whether interconnected or stand-alone. Also called
  DODIN (JP 6-0). This includes owned and leased communications and computing systems and services,
  software (including applications), data, security services, other associated services, and national security
  systems. Department of Defense information network operations are operations to secure, configure, operate,
  extend, maintain, and sustain Department of Defense cyberspace to create and preserve the confidentiality,
  availability, and integrity of the Department of Defense information network. Also called DODIN operations
  (JP 3-12). DODIN operations provide authorized users at all echelons with secure, reliable end-to-end
  network and information system availability. DODIN operations allow commanders to effectively
  communicate, collaborate, share, manage, and disseminate information using information technology
  systems.
  2-6. Signal forces install tactical networks, conduct maintenance and sustainment activities, and security
  evaluation and testing. Signal forces performing DODIN operations may also conduct limited DCO-IDM.
  Since both cyberspace security and defense tasks are ongoing, standing orders for DODIN operations and
  DCO-IDM cover most cyberspace security and initial cyberspace defense tasks.
  2-7. The Army secures the DODIN-A using a layered defense approach. Layered defense uses multiple
  physical, policy, and technical controls in to guard against threats on the network. Layering integrates people,
  technology, and operational capabilities to establish security barriers across multiple layers of the DODIN-
  A. Various types of security barriers include—
  * Antivirus software.
  * Firewalls.
  * Anti-spam software.
  * Communications security.
  * Data encryption.
  * Password protection.
  * Physical and technical barriers.
  * Continuous security training.
  * Continuous network monitoring.
  2-8. Security barriers are protective measures against acts that may impair the effectiveness of the network,
  and therefore the mission command system. Additionally, layering includes perimeter security, enclave
  security, host security, physical security, personnel security, and cybersecurity policies and standards.
  Layering protects the cyberspace domain at the physical, logical, and administrative control levels.
  DEFENSIVE CYBERSPACE OPERATIONS
  2-9. Defensive cyberspace operations are missions to preserve the ability to utilize blue cyberspace
  capabilities and protect data, networks, cyberspace-enabled devices, and other designated systems by
  defeating on-going or imminent malicious cyberspace activity (JP 3-12). The term blue cyberspace denotes
  areas in cyberspace protected by the United States, its mission partners, and other areas the Department of
  Defense may be ordered to protect. DCO are further categorized based on the location of the actions in
  cyberspace as—
  * DCO-IDM.
  * DCO-RA.
  DEFENSIVE CYBERSPACE OPERATIONS-INTERNAL DEFENSIVE MEASURES
  2-10. Defensive cyberspace operations-internal defensive measures are operations in which authorized
  defense actions occur within the defended portion of cyberspace (JP 3-12). DCO-IDM is conducted within