Network outages damage customer relationships, revenue, and reputation. Redundancy planning eliminates single points of failure that transform minor problems into service-affecting incidents.
Identifying Single Points of Failure
Every network has them initially. Trace the path from any customer to the internet; every unique component represents potential failure. Routers, switches, fiber paths, power supplies, even physical locations—any non-redundant element is a risk.
Failure modes extend beyond equipment. Power outages, fiber cuts, cooling failures, and human errors cause incidents. Redundancy planning addresses the full failure spectrum.
Layered Redundancy
Device redundancy uses paired equipment. Two routers, each capable of handling full load, with automatic failover between them. VRRP, HSRP, or proprietary protocols provide gateway redundancy. Stacked switches or MLAG configurations provide layer 2 resilience.
Path redundancy ensures multiple physical routes exist. Diverse fiber paths from different entry points survive individual cable cuts. Transit from multiple providers with appropriate BGP configuration maintains internet connectivity despite provider issues.
Power redundancy combines UPS systems, generators, and diverse utility feeds. Runtime requirements determine battery sizing. Generators need fuel supplies and regular maintenance testing.
Cost-Benefit Analysis
Redundancy isn't free. Every duplicated component represents investment that could fund other priorities. The question is whether the protection justifies the cost.
Calculate expected downtime cost. Multiply average incident duration by incident frequency by per-hour impact. Compare against redundancy investment to assess payback periods.
Testing Validates Design
Untested redundancy is theoretical. Actual failover tests—disconnecting primary equipment, simulating provider outages—verify that backup systems engage as designed. Many organizations discover failover problems only during real incidents; planned testing avoids this.
Document recovery procedures. During failures, stress impairs decision-making. Written procedures ensure staff execute correctly even under pressure.
Progressive Implementation
Perfect redundancy isn't achieved overnight. Prioritize based on impact and likelihood. Core routing typically warrants earliest investment; edge equipment serving few customers may tolerate more risk. Improve progressively as budget allows.