Why Network Segmentation Projects Fail: Four Patterns

Cisco's 2026 Segmentation Report analyzes 400 failed network segmentation projects and identifies four distinct failure patterns: Perfect Storm (50%), Diffuse Friction (33%), Operational Drag (9%), and Scope & Visibility Trap (8%). Over 80% of failures involve multiple simultaneous issues rather than a single root cause. Campus networks and Layer 2 approaches are especially failure-prone, while workload type has no significant effect. A key finding is that 70% of practitioners attributed failure to general IT project management issues even when segmentation-specific problems were the real cause — highlighting that good project management is necessary but not sufficient.