My ISP is TalkTalk and I have one of their FTTC packages. With that I also have their YouView TV service. Before getting this service I used my own routers, as ISP supplied ones didn't have the features I wanted. I would like to continue doing this however I've found if I swap the router for a different one the TV service stops working (Internet access works fine). I believe this may have something to with multicast, but my knowledge on multicast is slim at best.
I've used DD-WRT and OpenWRT routers in the past, and they support multicast in a fashion so I'd like to use these if I can. If not that's ok, but I would like to swap the router.
Is this possible, and if so what do I need to do to extract and replicate the settings to make the TV work?