How to forward upnp service

Question

Hello,
I have setup upnp server (minidlnad) on my one internal network and I would like to forward it to the another network, but I can't get it work.
All machines on my network has simple statefull firewall configuration (from guide at archwiki).
UPnP server:
IP Address: 10.10.10.3
Firewall rules:
-A TCP -p tcp -m tcp --dport 8200 -j ACCEPT
-A UDP -p udp -m udp --dport 1900 -j ACCEPT
as long as client device is on network 10.10.10.0/24 it discovers this server without any problem, and I would like to allow devices on my second network 10.1.1.0/24 to be able to connect to this server.
So i have setup a forwarder. This machine has connection to both network 10.10.10.0/24 and 10.1.1.0/24 it and see and comunicate with all devices on both networks, it also forward some other services and these works like a charm.
Forwarder:
IP Addresses: 10.10.10.240, 10.1.1.1.1
Firewall rules (Forward policy is ACCEPT):
-A PREROUTING -s 10.1.1.0/24 -i br0 -p tcp -m tcp --dport 8200 -j DNAT --to-destination 10.10.10.3:8200
-A PREROUTING -s 10.1.1.0/24 -i br0 -p udp -m udp --dport 1900 -j DNAT --to-destination 10.10.10.3:1900
* br0 is correct interface
any idea why I can't discover this upnp server on my second network? Is there anything else I need to forward?
Thanks

Answer 1

Use a) multicast or b) a relay.