What is the default port used by CUPS (Common Unix Printing System)?

The Common Unix Printing System (CUPS) uses port 631 by default. This port is designated for the Internet Printing Protocol (IPP), which is the main protocol that CUPS relies on for managing print jobs and communicating with printers over the network. The use of port 631 allows for standardization across various systems and ensures compatibility with different printing environments.

While other ports are associated with different protocols and services—such as port 80 for HTTP, port 443 for HTTPS, and port 22 for SSH—port 631 is specifically reserved for CUPS and the IPP it utilizes for printer management. Thus, recognizing port 631 as the default port for CUPS is crucial for understanding how printing services are typically configured and accessed in a Linux environment.