Life Cycle Management

Network Life Cycle Management (LCM) is the systematic approach to managing network infrastructure from initial planning through decommissioning. This process ensures networks remain secure, efficient, and aligned with business requirements throughout their operational lifetime.

Life Cycle Phases

• Plan Phase: Requirements gathering, network design, and resource allocation

  • Define business objectives and technical requirements
  • Conduct site surveys and capacity planning
  • Create network topology diagrams and IP addressing schemes
  • Example: Planning a campus network upgrade from 100Mbps to 1Gbps switching

• Design Phase: Detailed technical specifications and architecture decisions

  • Select appropriate protocols (OSPF vs EIGRP for routing)
  • Design redundancy and failover mechanisms
  • Plan security policies and access control lists (ACLs)
  • Critical decision point - changes after implementation are exponentially more expensive

• Implement Phase: Physical deployment and initial configuration

  • Install hardware and configure basic connectivity
  • Deploy routing protocols with proper metrics and administrative distances
  • Configure VLANs, trunking, and inter-VLAN routing
  • Example: Configuring switchport mode trunk on inter-switch links

• Operate Phase: Day-to-day network management and monitoring

  • Monitor performance metrics (utilization, latency, packet loss)
  • Manage user access and security policies
  • Perform routine maintenance and updates
  • Mission-critical networks require 24/7 monitoring (like military command centers)

• Optimize Phase: Performance tuning and efficiency improvements

  • Analyze traffic patterns and adjust QoS policies
  • Optimize routing tables and convergence times
  • Implement load balancing where appropriate
  • Used when networks show performance degradation or capacity constraints

Management Activities

Key Management Concepts

• Change Management: Controlled process for network modifications

  • All changes must be documented and approved (especially in government/enterprise)
  • Implement change windows during low-traffic periods
  • Maintain rollback procedures for failed changes
  • Example: Upgrading IOS requires testing in lab environment first

• Asset Management: Tracking network devices and their lifecycle status

  • Monitor hardware warranty and end-of-life (EOL) dates
  • Track software versions and security patch levels
  • Maintain spare parts inventory for critical components
  • Proactive replacement prevents unexpected outages

• Documentation Management: Maintaining accurate network records

  • Keep current network diagrams and IP address management (IPAM)
  • Document standard configurations and procedures
  • Maintain contact lists for vendors and support teams
  • Outdated documentation is worse than no documentation

Vocabulary

• MTTR (Mean Time To Repair): Average time to restore service after failure
• MTBF (Mean Time Between Failures): Average operational time between failures
• SLA (Service Level Agreement): Contractual uptime and performance guarantees
• RTO (Recovery Time Objective): Maximum acceptable downtime after incident
• RPO (Recovery Point Objective): Maximum acceptable data loss timeframe

Notes

• Life cycle management becomes critical as networks scale beyond 50+ devices
• Document everything during implementation - memory fades but networks must be maintained for years
• Plan for technology refresh cycles (typically 3-5 years for switches, 5-7 years for routers)
• Government and military networks often require longer lifecycle planning due to budget constraints and security clearance requirements
• Use network management platforms (SolarWinds, PRTG, Nagios) for larger deployments rather than manual monitoring
• Always test changes in lab environment first - production networks are unforgiving of mistakes
• Consider automation tools (Ansible, Python scripts) for repetitive lifecycle tasks as network complexity grows