CREST Practitioner Security Analyst (CPSA) Practice 2026 – All-in-One Guide to Mastering Exam Success!

The protocol that utilizes port 67 is the DHCPv4 Server, which is essential in dynamic IP address allocation. The Dynamic Host Configuration Protocol (DHCP) is used to automatically assign IP addresses and other network configuration parameters to devices (clients) on a network. When a device connects to the network and requests an IP address, it sends a DHCP Discover message to the server, which listens for requests on port 67.

In addition to that, the other protocols listed operate on different ports: DNS typically uses port 53 for name resolution, FTP uses ports 20 and 21 for file transfers, and HTTP operates over port 80 for web traffic. This distinction in port assignments is critical for proper network management and function, highlighting why recognizing the specific protocols and their respective ports is important for security analysts.