So, on many routers at the end, I block everything on the forward chain. I've noticed a few issues though recently around printing in Remote Desktop using Easy Print. Apparently easyprint uses the RDP port which is tcp/udp 3389. However, when I have a forward block at the end, printing stops, or acts very weird.
Looking at the traffic dropped, I can't see anything really that would show me why this is happening.
Is it best practice to drop the forward chain at the end, and do you you have any idea what's going on here? I'm wondering if it's invalid packets being dropped as I have an established/related rule at the top...