Hello people and I must apologise if this is already posted up somewhere but, I really need some help.

I have set my Virgin Media hub 3.0 to modem mode and wired up an Asus AC86U. I have gone through some settings for my wi-fi and the only major thing I have chaged is the port forwarding for my ps4 using WAN > Virtual Server/Port Forwarding and then putting in my ip, subnet, gateway, Prime and secondary DNS. The next day Virgin Media sent me an email about Multicast DNS vulnerability and blocking or deleting Port 5353 which I couldn't see or know what to do. Today i have received a letter telling me about Multicast DNS vulnerability again. I am a total noob when it comes to anything like this and I thought doing the forwarding for my ps4 would help with the nat type error. Can anyone please help me out and possibly give me a step by step on what I need to do? Everything on my router is currently at default apart from DoS protection that I enabled.

Thank you so much for any help given.

Jamie.