You have:

1. A Roomba vacuum. (I was working with an i-series when I wrote this. Maybe this applies to other models as well.)
2. A firewall or router between your Roomba and your mobile device. (Maybe the two are on different wifi networks as would be the case if you have a network set aside for IoT devices.)
3. An iRobot app that gets stuck at Verify password when setting up the Roomba.

In a throwback to the problems I dealt with using AirPlay across VLANs, I recently jumped through similar hoops for Sonos speakers. There are many forum and blog posts out there that describe (or attempt to describe) how to make this work, however all of the ones I read suffered from one or both of these problems:

1. Their instructions had errors (eg, reversing the upstream and downstream interfaces when talking about multicast).
2. They don't have a diagram of traffic flow! Every network engineer knows that a diagram is a must when trying to understand how two systems are talking to each other.

This post will dive deep on what's happening on the wire when a Sonos controller (eg, your mobile phone running the Sonos app) tries to talk with the players (the speakers) on the network. The focus will be how to make this process work when those two devices are in different VLANs.

What you read below works successfully with Sonos Beam, Sonos Sub, and Sonos Move using the Sonos S1 app.

The OpenBSD routing table can be carved into multiple virtual routing tables allowing complete logical separation of attached networks. This article gives a brief overview of rtables and explains how to successfully leak traffic between virtual routing domains.