oh well, I completely overlooked the “DROP_INPUT” snippet in the screenshots provided.
May I ask you to edit the firewall rule once more, and set its destination to “firewall”, and then choose IPFire’s RED interface?
The reason for this is the underlying behaviour of
iptables: Rules having the multicast range set as its destination are placed into the FORWARD chain. However, since IPFire interprets these as being incoming connections, they actually hit the INPUT chain. This is why the rule I proposed in the first place never triggered, and you folks continued to observe these log entries.
Sorry about this. Will have a cup of coffee first next time.
Thanks, and best regards,