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Network+ Domain 3 - Network Operations (19%)

Documentation, monitoring, availability, and the organizational paperwork. Light on technology, heavy on terminology the exam expects you to distinguish precisely.

Documentation

  • Physical network diagram - cabling, ports, racks, and where equipment physically sits.
  • Logical network diagram - IP subnets, VLANs, and routing relationships, independent of physical layout.
  • Rack diagram - elevation showing what occupies each rack unit.
  • Wiring and port location diagram - which wall port terminates on which patch panel port and switch port.
  • IP address management (IPAM) - the authoritative record of allocated addresses and subnets. Prevents duplicate assignments.
  • Asset inventory - hardware and software owned, with lifecycle status.
  • Baseline configuration - the approved standard configuration for a device class. Drift from baseline is a change to investigate.
  • Site survey report - documented wireless coverage and interference measurements.
  • Audit and assessment report - findings from a formal review against a standard.

Monitoring

  • SNMP - polls devices for status. Traps are unsolicited alerts from the device.
  • Syslog - centralized event logging. Severity runs 0 (emergency) to 7 (debug); lower numbers are more severe.
  • NetFlow / sFlow / IPFIX - flow data describing who talked to whom, how much, and for how long. Flow data answers bandwidth questions that packet capture is too heavy for.
  • Packet capture - full payload, highest detail, highest storage cost.
  • SIEM - aggregates and correlates logs, generating alerts.
  • Network discovery - identifying what is present, actively by scanning or passively by observing.

Performance metrics

  • Bandwidth - theoretical maximum capacity of a link.
  • Throughput - the data rate actually achieved.
  • Latency - delay for a packet to travel end to end.
  • Jitter - variation in latency between packets. The metric that ruins voice and video even when average latency is acceptable.
  • Packet loss - packets that never arrive. Small percentages devastate TCP throughput.

Voice and video are the usual context for jitter questions; a bulk file transfer cares about throughput and is largely indifferent to jitter.

Availability and redundancy

  • High availability (HA) - designing so that a single failure does not cause an outage.
  • Active-active - all nodes serve traffic; provides load sharing and failover.
  • Active-passive - a standby takes over on failure; simpler, wastes capacity.
  • Clustering - multiple systems presenting as one service.
  • NIC teaming - bonding multiple network adapters on a host for redundancy or throughput.
  • First hop redundancy (FHRP) - protocols such as VRRP and HSRP present a virtual gateway IP shared by two routers, so gateway failure is transparent.
  • Load balancing - distributing requests across servers.
  • Cold, warm, and hot site - a cold site is space and power only, a warm site has equipment but stale data, a hot site is ready to take traffic immediately. Cost rises with readiness.

Recovery metrics

  • RTO (Recovery Time Objective) - how quickly service must be restored.
  • RPO (Recovery Point Objective) - how much data loss is acceptable, expressed as time.
  • MTBF (Mean Time Between Failures) - average operating time between failures of a repairable system.
  • MTTR (Mean Time To Repair) - average time to restore after a failure.

RTO and RPO are the pair most often confused. RTO is about time to restore; RPO is about data lost. A one-hour RPO means backups at least hourly.

Organizational documents and policies

  • SLA (Service Level Agreement) - a commitment to a measurable service level, usually with penalties.
  • MOU (Memorandum of Understanding) - a statement of intent between parties, generally not legally binding.
  • NDA (Non-Disclosure Agreement) - confidentiality obligations.
  • AUP (Acceptable Use Policy) - what users may and may not do with company systems.
  • BYOD policy - terms for personal devices on the corporate network.
  • SOP (Standard Operating Procedure) - the documented way a routine task is performed.
  • Onboarding and offboarding - account and asset provisioning and, critically, revocation.
  • Data loss prevention (DLP) - controls detecting and blocking sensitive data leaving the organization.

Change and configuration management

  • Change management - the process for requesting, assessing, approving, and recording changes.
  • Change request - the record: reason, scope, risk, rollback plan, and approver.
  • Rollback plan - how to undo the change if it fails. Required before approval, not written during the outage.
  • Maintenance window - the agreed period for disruptive work.
  • Configuration management - keeping device configurations consistent, versioned, and recoverable.
  • Configuration drift - accumulated undocumented differences from the baseline.

Network management methods

  • In-band management - managing a device over the production network. Simple, but unavailable exactly when the network is broken.
  • Out-of-band management - a separate path, such as a console server or dedicated management port, that works when the production network does not.
  • Jump box / bastion host - a hardened intermediary through which administrative access is funnelled.
  • VPN - encrypted remote access. Site-to-site connects networks; client-to-site connects individual users.

Exam pointers

  • Learn RTO versus RPO to the point of reflex. They are among the most reliably tested definitions in the domain.
  • MTBF measures reliability, MTTR measures repair speed. A question about how long the business waits is MTTR.
  • Jitter is the answer for choppy voice or video when latency looks fine.
  • Any question about managing a switch during a network outage points to out-of-band management.
  • MOU is not binding; SLA is. Questions sometimes hinge on that distinction.

Official documentation

📖 CompTIA Network+ N10-009 objectives - authoritative domain list 📖 NIST SP 800-34 - contingency planning, covers RTO and RPO