What is required to scan both UDP and TCP ports?

What is required to scan both UDP and TCP ports?

• A. -sU
• B. -p
• C. -sU with at least one TCP scan type such as -sS, -sF, or -sT
• D. -sT

Answer: (C)

The main idea is that UDP and TCP scans are controlled by different switches, so to cover both you must enable UDP scanning and also pick a TCP scan method in the same command. UDP scanning uses a switch like -sU, which targets UDP ports, but to scan TCP ports you need a TCP scan type such as -sS (SYN), -sF (FIN), or -sT (connect). The only option that combines both is to use -sU together with at least one TCP scan type in the same run. For example, using -sU -sS target will inspect both UDP and TCP ports. The other options fail to scan one of the protocols: -sU alone scans only UDP, a plain -sT covers TCP only, and -p is just for port ranges, not for selecting protocols.

The main idea is that UDP and TCP scans are controlled by different switches, so to cover both you must enable UDP scanning and also pick a TCP scan method in the same command. UDP scanning uses a switch like -sU, which targets UDP ports, but to scan TCP ports you need a TCP scan type such as -sS (SYN), -sF (FIN), or -sT (connect). The only option that combines both is to use -sU together with at least one TCP scan type in the same run. For example, using -sU -sS target will inspect both UDP and TCP ports. The other options fail to scan one of the protocols: -sU alone scans only UDP, a plain -sT covers TCP only, and -p is just for port ranges, not for selecting protocols.