VNC is a protocol used to connect remote systems with GUI. It is especially popular in Linux world but supports other platforms like Microsoft and MacOS. The default port numbering for multiple VNC services can be tricky for new comers. In this tutorial we will look port and numbering about VNC.
The default port for VNC server is TCP 5900 . This port can be changed if we need. Especially if this VNC service is open to the internet or insecure networks changing default port will make our system more secure.
We can create new desktop sessions with a single VNC daemon or service. We can configure new desktop and listen new TCP port for the new sessions. Newly added ports will get BASE PORT NUMBER +1 . Which means if BASE PORT NUMBER is 5900 new desktop session will be 5901. This will increment one by one if we add new desktop sessions.
我们可以使用单个VNC守护程序或服务创建新的桌面会话。 我们可以配置新的桌面,并为新会话监听新的TCP端口。 新添加的端口将获得BASE PORT +1。 这意味着如果BASE PORT NUMBER为5900,则新的桌面会话将为5901。如果我们添加新的桌面会话,则它将一一递增。
VNC Web界面端口5800 (VNC Web Interface Port 5800)
VNC can be generally used with desktop client applications. But some VNC server software provides web based client which do not needs VNC desktop client. Web VNC clients generally uses TCP 5800.
VNC通常可以与桌面客户端应用程序一起使用。 但是某些VNC服务器软件提供了基于Web的客户端,不需要VNC桌面客户端。 Web VNC客户端通常使用TCP 5800 。
检查默认端口和其他端口 (Check Default and Other Ports)
We can check wheter remote VNC server port is open with telnet . In this example we will check remote system 10.0.2.27 port 5900 is open.
We can see that telnet is connected successfully and remote VNC server provided some response like RFB 003.008 which means remote port is a VNC server and up.