IP Architecture / Design Cheetsheat

Cheat sheet of IP Architecture / design considerations

Still Draft / Work in Progress

Network outcomes / optimizations

  • Deliver packets to intended destinations
  • Minimize dropped & looping packets
  • Minimize network induced errors in packets
  • Minimize latency & jitter were applicable
  • Network reliability & availability
  • Network efficiency & utilization
  • Support intended services

Considerations

Ultimately, network architects/engineers are endeavoring to support the mission & desired outcomes of the entity they work for, with finite resources. As desired outcomes and available resources vary from entity to entity, levers pulled, and approaches employed will vary as well. As equipment, software, protocols, and tools evolve, the options continue to change.

TopicConsiderationApproaches
Failure domains
(modularity)
Limit impact of failureAutonomous systems
Routing Areas
Virtual topologies
Coupling
(surface / interactions)
Loose coupling–>Reduce complexityBGP is considered good at loose coupling
Information hygiene
(state)
Limit control plane information to what is necessaryRoute aggregation
Default static
Network sizing
(capacity)
Economical capacity that is complexity reducing (CPU, memory, link, switching,…)Reduce resource stress through increased capacity
Convergence
(packet loss)
Minimize lost / looping packetsTimers
Loop free alternatives
Source routing
Move complexity
(practical tradeoffs)
Protocol vs Network DesignWhere do practicalities dictate complexity is best dealt with
Policy
(intent)
Deviate from default behaviorFilters
Policy configuration