Streaming from Jellyfin to Chromecast

[Uberkeyser]

I am trying to use Jellyfin as a Media server (on a Raspi)  to distribute content (including DVB-C live channels) to local devices, mainly to Google Chromecasts.
I keep reading that streaming from Jellyfin to Chromecasts was tricky and required weird tasks, involves setting up a local DNS server that has some kind of facilitated https-certificates for the Jellyfin server and forwarding router ports in order to trick the Google devices to connect to that DNS server instead of Google's DNS servers..... all of which is weird to me not because it sounds complicated but because it sounds like compromizing my local network's security.

While I understand the explanation (Chromecasts have hardcoded DNS servers (8.8.8.8 and 8.8.4.4) and wont connect to anything else); I wonder why other Upnp servers (namely KODI) can stream to Chromecast entirely in the local network, nothing being connected to the Internet, leave alone registered on Google'S DNS servers. (Before you ask why I am not simply using KODI then, KODI cannot transcode )

Can anyone enlighten me how KODI does it, and why Jellyfin can't?

[niels]

I'm not sure how it works with Kodi, but for other media servers they often use proxy everything through their cloud. Jellyfin doesn't have this, media is loaded directly from your server when you cast. For that network access Google uses their own nameservers (8.8.8.8) and require a secure connection (https) so your DNS should resolve properly with a valid certificate.

[Uberkeyser]

Thanks, Niels. But it does not explain the phenomenon. For complete disclosure: I am using Home Assistant to trigger a stream from KODI (DLNA/Upnp) to Chromecast. It works like a charm, as long the source is using a codec that Chromecast can handle so no transcoding necessary. But neither KODI nor Home Assistant is connected to a cloud (That's a fact not a guess)
As an explanation I was rather thinking of something like UPnP using neither domain names nor https, hence Chromecast's dendency on Google's DNS is irrelevant for Upnp. But then this should also apply to Jellyfin.