Port 5900
VNC Remote Desktop
Virtual Network Computing (VNC) allows users to remotely control another computer’s desktop across networks or the internet. Operating primarily on port 5900, VNC is widely compatible, supporting various implementations including Apple Remote Desktop. It facilitates graphical desktop sharing, enabling seamless access and management regardless of physical location..
Technical Details
Overview
Virtual Network Computing (VNC) is a cross-platform protocol that facilitates remote graphical desktop sharing by transmitting keyboard and mouse events between client and server, paired with a framebuffer update mechanism. The default port it uses is 5900, with additional ports (5901, 5902, etc.) for concurrent sessions.
Protocols and Implementations
VNC is platform-agnostic and typically relies on the Remote FrameBuffer (RFB) protocol, which is simple yet versatile. Multiple open-source and commercial implementations exist, notably RealVNC, TightVNC, UltraVNC, and Apple Remote Desktop. It supports desktop sharing over both TCP and UDP and can be tunneled through encrypted connections such as SSH or VPN.
Use Cases and Connectivity
VNC is popular in IT administration, end-user support, education, and remote work scenarios. While primarily used over TCP for reliable session delivery, some implementations experiment with UDP for performance improvements. SCTP support is uncommon.