Router doesn't see my NAS at home

I just about a new router Asus AC66u and I plugged in my NAS directly to it. But the router doesn't see my NAS, the IP is set on my NAS.

I tried to ping the NAS but no reply, and I disabled the firewall on the router and also added the IP for the NAS to my port forwarding list but still doesnt work.

what else i can do to fix this situation.

thanks