AFP over TCP

AFPOVERTCP (Apple Filing Protocol over TCP) is a protocol used primarily for file sharing between macOS systems over a network. It operates over TCP/IP, providing a reliable way to share files and directories. This service is essential for environments where macOS systems need to communicate and share resources efficiently.

What is AFP over TCP

AFPOVERTCP, or Apple Filing Protocol over TCP, is a network protocol that facilitates file sharing between macOS systems. It operates over TCP/IP, which is the suite of communication protocols used to connect network devices on the internet. AFPOVERTCP is particularly important in environments where multiple macOS systems need to share files and directories seamlessly.

The protocol was developed by Apple Inc. and has been a core component of macOS networking for many years. It allows users to access files on remote macOS systems as if they were on their local machine, providing a user-friendly and efficient way to manage files across a network.

AFPOVERTCP supports various features such as file locking, which prevents multiple users from editing the same file simultaneously, and resource forks, which are used by macOS to store additional information about files. These features make AFPOVERTCP a robust solution for file sharing in macOS environments.

Despite its advantages, AFPOVERTCP has seen a decline in usage with the advent of more modern protocols like SMB (Server Message Block), which offers better cross-platform compatibility. However, it remains a valuable tool for macOS-centric networks.

AFP over TCP runs on TCP and UDP port 548 and is official IANA port.

Security risk

If port 548 is open and the AFPOVERTCP service is running, it could expose the system to unauthorized access and data breaches. Attackers could exploit vulnerabilities in the protocol to gain access to sensitive files and directories. It is crucial to secure this port with proper firewall rules and authentication mechanisms to mitigate potential risks.

In our UFW tutorial you can follow instructions how you can configure UFW to close port 548. Use StackChanges to monitor if the AFP over TCP port is closed and stays closed. StackChanges will send an alert if port 548 is open again.