DNS only uses UDP/TCP on port 53. It uses both TCP and UDP, though TCP is normally used to pass zone information between the primary and secondary DNS server, it can be used to query for host information; in particular, where it is a cluster name, and all IP numbers belong to different members of the cluster. TCP is available for long lists (even though it isn't fully supported by clients yet).
Not sure what you are referring to by "Dynamic RPC port", as RPC is the acronym for remote procedure call...
Last edited by jpollard; 03-02-2015 at 11:22 AM.