Goodbye, Leaf-and-Spine Networks?
Summary
Ivan Pepelnjak analyzes a new AWS paper claiming lean, high-throughput data center fabrics with fewer routers. He argues that leaf-spine is not obsolete and explains concepts like unequal-cost multipathing and virtual circuits, while offering plausible explanations for the reported gains. The piece concludes that such approaches may be worthwhile for very large fabrics but are not universally superior to well-implemented leaf-spine designs.