CREST Practitioner Security Analyst (CPSA) 2026 – 400 Free Practice Questions to Pass the Exam

The service that operates on Port 67 (UDP) is the DHCP Server. This port is designated for the Dynamic Host Configuration Protocol (DHCP), which is used to assign IP addresses and other network configuration parameters dynamically to devices on a network.

In a typical DHCP transaction, the server listens on UDP port 67 for requests from clients. When a client device wants to join a network, it sends a request to discover available DHCP servers. The server, upon receiving this request, responds with an IP address and configuration settings, allowing the client to configure its network settings automatically.

Understanding this is vital because it highlights the specific role of the DHCP server in managing IP assignments within a network, differentiating it from clients and other services that operate on different ports or protocols. This knowledge is essential for ensuring proper network functionality and troubleshooting any network configuration issues.