I was excited last week when I saw that Roon now supports Chromecast devices. I bought a Chromecast Audio and set it up. My Roon server could not find the device, despite the fact that phones on my network can see and play to it.
The issue is that the Chromecast sends it’s discovery response with a TTL of 1 on its packets. If the Chromecast and Roon server connect to the same router directly, this isn’t an issue. If you have a more complicated network where there are more smart devices between the router and the Roon server, the TTL of 1 will cause the network discovery packets to get dropped before they make it back to the Roon server. This could be something like an extra router acting as a wireless bridge, a level 3 switch, or any type of setup where the Roon server and Chromecast are on different subnets.
If the packets get dropped, the Roon server has no way to know the Chromecast is there. It can still talk to the Chromecast from a technical standpoint, but has no way to discover it. I would like to see a work around in Roon for this. Add an advanced option to let us specify IP addresses for Chromecast devices that are there but fail to be discovered due to the TTL issue. If we tell Roon manually the address of the device, Roon should still be able to play to it.
Edit: I want to clarify that this is not a problem in Roon. This is poor behavior on Google’s part. Unfortunately, getting Google to change it would be nearly impossible. I figure Roon is responsive, and stands a better chance of implementing a work around.