Plex spams broadcast messages to the network by default. My understanding is that the purpose is to discover Plex clients so they don’t have to enter the IP. That’s fine, although it is awfully aggressive about it.
But when you disable GDM, it doesn’t stop. That I don’t understand. That seems like a bug. If I tell it not to do network discovery, why is it still obsessively doing network discovery? Is there some utility to that?
It is filling up a variety of logs around my network. Linux systems with UFW, when you dmesg, it is like one real message, then 40 messages about blocking Plex spam before you get to the next real message. Same with the alerts on my SIEM. The SIEM considers it, even with GDM disabled, to be so excessive that it is likely an attack… Same with some of my network firewalls- all log it, and some classify it as a threat. It just is not polite network behavior. At the very least, I think we need the ability to disable it, if we’re willing to give up the benefits of GDM, which I am: I have one TV that uses Plex. It already knows the IP. The discovery serves no purpose for me.
This issue has been raised many times, for 15+ years. Sometimes people propose a solution of putting it on a VLAN. Sure, that would work, if you have a router that handles VLANs, but an application that is behaving so badly that it needs to be separated from the other children is an application that should try to behave better, IMO. It seems simple to just have disabling GDM actually stop the GDMing.
