Hey dude, how can you block the facebook and youtube by the policy routing? Do you mean the function App Control?

I remember that the ER5120 can support up to 1024 IP address. Hope this can help you.

Josh wrote Hi Panda, Thank you for your reply. I'm a little bit confused about the source IP. Both WAN has a different Static IP. Which one should I input? Hi Josh The source IP should not be the WAN...

You just need to configure the Policy Routing. Put in your source IP of the PC, and choose one of the WAN port you want to restrict to. Leave the destination IP as 0.0.0.0. Hope can help you.

hey dude,I suggest you go to contact the Supporter of TP-Link directly.

Hey dude You must know the NAT throughput is just 96M, if your 4 bandwidths up to 100Mbps, the router cannot match your need.