DNS can use the services of ________ using the well-known port 53.a.UDPb.none of the abovec.either (a) or (b)d.TCP

Break Down the Problem

1. Identify the protocols associated with DNS.
2. Determine the correct port number used for DNS communication.

Relevant Concepts

• DNS (Domain Name System) primarily uses two types of transport protocols: UDP and TCP.
• UDP is commonly used for queries, while TCP is used for tasks such as zone transfers or when the response data size exceeds 512 bytes.

Analysis and Detail

1. UDP: DNS primarily operates using the User Datagram Protocol (UDP) on port 53 for most of its activities, specifically for DNS queries.
2. TCP: The Transmission Control Protocol (TCP) is also associated with DNS on port 53 but is less commonly used than UDP. It is used when responses are larger than 512 bytes or during zone transfers.
3. Both protocols utilize port 53, but UDP is the primary mode of operation. The question asks for the type of service DNS can use.

Verify and Summarize

• Given that both UDP and TCP use port 53 for DNS services, the best choice reflecting this understanding would be "either (a) or (b)" since both are valid for different scenarios.

Final Answer

c. either (a) or (b)