We suspect the device may have been misconfigured by you, someone in your household or without your knowledge. If the settings are left unchanged they can be exploited to unwittingly participate in malicious activities, for example a Distributed Denial of Service (DDoS) attack.
I'm not sure if this is 100% the case here; but often when people do things such as running nodes on their home network (and especially anything to do with tor/ other "nefarious" traffic)- these are send out in "error" -
they simply see a huge influx of traffic going through your network, due to the node you have running over tor, and because it's running over tor, it's often seen by the internet provider as "malicious" traffic. Hence, they ask you to close your ports, and check your firewall, as is mentioned here;
https://www.virginmedia.com/help/multicast-dns-vulnerability-alertYou could try to do so (and by that i mean fixing the multicast "vulnerability") but i'm afraid you'll break your node in the process of doing so. (As running your node is most likely what sent out the warning in the first place; but; as i said; i'm not 100% sure.)
