Hell is other networks

What this episode covers

Bryan Cantrill and Adam Leventhal of Oxide Computer Company are joined by Levon Tarver, Alan Hanson, Will Chandler, and Trey Aspelund to discuss a customer's pathological network issue involving high packet loss during VPC-to-VPC hairpinning traffic. The team identified that Cisco Nexus switches were punting ICMP redirect packets to the CPU, which became a bottleneck under high throughput, causing severe packet loss. The resolution involved disabling IP redirects on the customer's switch interfaces, a fix that also led to improvements in Oxide's CLI logging and tooling.