A friend of mine sent me links to a new paper published by AWS engineers, and an associated LinkedIn post which claims: We got lean, resilient, massive aggregation fabrics that provide 33% better throughput with 69% fewer routers, savings 27% of costs, cutting power usage by 40%, and reducing CO2 emissions. The obvious question one should ask after reading the hyperventilated Radical Network Redesign blog post is thus: is this the end of leaf-and-spine networks? Of course not. Let’s go into the details.