Free Netflow | Collector _hot_

When a mysterious spike threatened to break the bank, a cash-strapped operations team built an enterprise-grade NetFlow collector using only open-source software and a refurbished server. Act 1: The Mystery of the Vanishing Bandwidth The trouble began on a quiet Tuesday. Our small but growing SaaS company, "LucidCloud," had just migrated its core infrastructure to a new colocation facility. The CEO was ecstatic about the new 10GbE uplink. The CFO, however, was not.

"Our bandwidth bill has tripled," she said, sliding a printout across the table. "Find out who’s downloading the Library of Congress." free netflow collector

Jake woke us up. "Uh, we're getting 300,000 flows per second." The collector was pinned. The Python script fell over. We realized our sampling rate was wrong. We tweaked the router from sampling-rate 1000 to sampling-rate 5000 (1:5000 packets). Suddenly, 6,000 flows/sec. Manageable. When a mysterious spike threatened to break the