Very small words and all capital letters



What type of service would commonly be used over UDP port 53?

A) CIFS

B) SMTP

C) DNS

D) RDP

E) I’m building a protocol that uses no abbreviations


The answer: C) DNS

Domain Name Service lookups are commonly seen on udp/53.

Want to know more? Watch “Common TCP and UDP Ports.”

TCP and UDP are the primary transport protocols used in today’s modern networks. In this videos, you’ll get an operational overview of the TCP and UDP protocols, and you’ll learn the TCP and UDP ports that will be important to know for your CompTIA A+ exam.