I am new to Roon and having some trouble. I installed Roon server on my Ubuntu server and everything seemed to work fine, but the next day Roon server would sometimes not connect and when it did it would not play music. I tracked it down to my pfSense box blocking it. I found if I allow udp port 10001 everything works. However, I think this may be due to mDNS and allowing port 10001 may not be the right fix. I am far from a network expert and I simply found where it was being blocked and added it as a new rule.
I think there are other ports involved.
Try a forum search if no one else chimes in.
UDP 9003, TCP 9100-9200 at least
Thank you. Added those and seems to work for now. I did remove the UDP 10001 rule.