Mangle and Port VNC (Virtual Network Computing) - MikroTik Script RouterOS
In computing, Virtual Network Computing (VNC) is a graphical desktop-sharing system that uses the Remote Frame Buffer protocol (RFB) to remotely control another computer. ... Popular uses for this technology include remote technical support and accessing files on one's work computer from one's home computer, or vice versa.
Port forward VNC (Virtual Network Computing):
/ip firewall mangle
add action=mark-connection chain=prerouting dst-port="5800" new-connection-mark=conn-VNC protocol=tcp
add action=mark-connection chain=prerouting dst-port="5800" new-connection-mark=conn-VNC protocol=udp
add action=mark-packet chain=prerouting connection-mark=conn-VNC new-packet-mark=VNC_pkt-up passthrough=no src-address=192.168.1.0/24
add action=mark-packet chain=prerouting connection-mark=conn-VNC dst-address=192.168.1.0/24 new-packet-mark=VNC_pkt-down passthrough=no