Yes of course I ignore them, but my HDD cannot. Since Plex is keeping writing these useless messages, the drive is unable to spindle down and enter power save.
There is no way to completely disable Plex’s use of SSDP discovery. It is used for other functions in addition to client discovery (which actually can be disabled). The best solution is likely for you to block the responses from these clients, or to UDP 1900 on your server, using iptables or UFW or whatever you use as a firewall. I give an example in this older post (it’s old, but was tested to work at the time).
It’s this setting under Settings → Network (uncheck it):
However, that is not enough. As I said above, there is no way to completely disable the server’s use of SSDP discovery. It is used for there functions which cannot be disabled (network tuner discovery being one notable example). The server will always send these discovery requests and attempt to validate the responses it receives. If you need to circumvent this behavior, you’ll have to employ some form of blocking. The example I link blocks SSDP responses from a specific IP address. You could also block outbound traffic from the server to UDP 1900.
Thanks. You’re right, disabling network discovery is not enough. If I block all traffic to and from incriminated IPs (as in; iptables -A INPUT -s 10.x.x.x -j DROP; iptables -A OUTPUT -d 10.x.x.x -j DROP), then the errors disappear and my HDD properly spins down and goes into power saving. But if I use the rules as in your older post, that’s not enough and I still see those errors. I’ll need to double check what traffic still passes when using your example rule (BTW you filter by source port 1900 but isn’t 1900 the dest port in SSDP notifications?)
In my earlier testing, UDP 1900 was also the source port of the replies from those devices; that was a targeted rule intended to block replies from a specific device.
