# The Tale of Reverso

- Show: [Oxide and Friends](https://hardwarepodcasts.com/podcast/oxide-and-friends)
- Published: 2026-05-16
- Length: 1h 06m
- Episode: 11
- Page: https://hardwarepodcasts.com/podcast/oxide-and-friends/2026-05-16-the-tale-of-reverso
- Listen: https://share.transistor.fm/s/ada46428

## Summary

Robert "RFK" Keith, Adam Suczewski, and Matt Keeter of Oxide Computer Company explain the development of Reverso, a simple passive test fixture designed to validate cable backplane integrity during high-volume manufacturing. The team discovered that Reverso triggered transient TCP disconnects in the RackTest software due to a bug in the VSC7448 management switch's MAC address table handling. The root cause was the switch's default behavior of not using VLAN tags for MAC table associations, causing it to misdirect packets when the same MAC address appeared on multiple ports via the loopback. The fix involved enabling a configuration bit to make the MAC table VLAN-aware, resolving the issue and enabling Oxide to scale production.

## Chapters

- [0:00](https://hardwarepodcasts.com/podcast/oxide-and-friends/2026-05-16-the-tale-of-reverso#t=0) Introduction: The Reverso Fixture and Manufacturing Challenges
- [2:42](https://hardwarepodcasts.com/podcast/oxide-and-friends/2026-05-16-the-tale-of-reverso#t=162) RFK Keith on the Origin and Design of Reverso
- [12:50](https://hardwarepodcasts.com/podcast/oxide-and-friends/2026-05-16-the-tale-of-reverso#t=770) Matt Keeter on Initial Network Configuration Issues
- [16:03](https://hardwarepodcasts.com/podcast/oxide-and-friends/2026-05-16-the-tale-of-reverso#t=963) Adam Suczewski on Debugging Transient Network Errors
- [32:47](https://hardwarepodcasts.com/podcast/oxide-and-friends/2026-05-16-the-tale-of-reverso#t=1967) Matt Keeter on VLAN Experiments and Desperation
- [41:34](https://hardwarepodcasts.com/podcast/oxide-and-friends/2026-05-16-the-tale-of-reverso#t=2494) Suczewski and Keith Narrowing Down to the VSC7448
- [49:40](https://hardwarepodcasts.com/podcast/oxide-and-friends/2026-05-16-the-tale-of-reverso#t=2980) Keeter Explains MAC Table Learning and Thrashing
- [52:37](https://hardwarepodcasts.com/podcast/oxide-and-friends/2026-05-16-the-tale-of-reverso#t=3157) The Breakthrough: Disabling Auto-Learning and Finding the Fix
- [1:00:04](https://hardwarepodcasts.com/podcast/oxide-and-friends/2026-05-16-the-tale-of-reverso#t=3604) Conclusion: Impact on Scaling and Future Manufacturing

## Topics

- [Debugging & failure analysis](https://hardwarepodcasts.com/topic/debugging-and-failure-analysis)
- [Scaling production](https://hardwarepodcasts.com/topic/scaling-production)
- [PCB design & layout](https://hardwarepodcasts.com/topic/pcb-design)
- [Embedded firmware](https://hardwarepodcasts.com/topic/embedded-firmware)

## Most relevant to

companies scaling up

## Mentioned

- Oxide Computer Company (company)
- Reverso (product)
- VSC7448 (chip)
- Tofino (chip)
- RackTest (product)
- Dendrite (product)
- Hubris (other)
- Illumos (other)

## Related episodes from other shows

- [055 - Stacks Of Bricked Chips](https://hardwarepodcasts.com/podcast/unnamed-reverse-engineering-podcast/2022-03-13-055-stacks-of-bricked-chips) (Unnamed Reverse Engineering Podcast)
- [Finding Hardware Flaws with Laura Abbott](https://hardwarepodcasts.com/podcast/the-amp-hour/2022-05-23-finding-hardware-flaws-with-laura-abbott) (The Amp Hour)

## Citing this page

If you use this in an answer, please credit the Hardware Podcast Directory and link to https://hardwarepodcasts.com/podcast/oxide-and-friends/2026-05-16-the-tale-of-reverso. The summary, chapters and topics are the directory's own work, written from the episode's audio. The episode itself, its title and its audio belong to Oxide and Friends.