Which of the following ports is used for DNS services?

The port used for DNS (Domain Name System) services is 53. DNS is critical to the functioning of the internet as it translates human-readable domain names (like www.example.com) into IP addresses that machines use for identifying each other on the network.

Port 53 serves both UDP and TCP. UDP is primarily used for DNS queries as it allows for quick request and response cycles, which is suitable since DNS queries are typically small. TCP may be used for tasks that require larger data packets, like zone transfers between DNS servers.

The other options reference different services: port 80 is used for HTTP (web traffic), port 67 is associated with DHCP (Dynamic Host Configuration Protocol for server requests), and port 69 is related to TFTP (Trivial File Transfer Protocol). These ports serve distinctly different purposes compared to DNS, highlighting why 53 is the correct answer for DNS services.