Configuring ACL on router for DNS

Am configuring a router to allow DNS queries from inside the network to an exterior DNS server. Have opened tcp/udp on port 53, however, DNS resolution is still not occurring. My understanding was that DNS was on port 53. Have tried dynamic DNS (port 2164) and multicast DNS (port 5353 and 5354) as well, still with no luck. Am at a loss as to what port needs to be open on the router to allow DNS queries. Thanks!