what is ports used for DNS service and which protocol ?

DNS use port53 , UDP for query and TCP for zone transfer

DNS Uses Port53 of TCP and UDP both

 

It Uses a Reliable Connection for DNS Replication update and for reliable connection is uses TCP otherwise UDP.

 

UDP protocol port53

DNS primarily uses User Datagram Protocol (UDP) on port number53.
Transmission Control Protocol (TCP) is used when response data size exceeds512 bytes(zone transfers).