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Port forwarding for VNC, RDP, HTTP, HTTPS and more

qbee allows you to forward any port and service from other edge devices to your local machine

This article explains the prerequisites for being able to use ssh port forwarding and explains common services that are used with that. WIth qbee you can forward services from ports on other devices in the same local edge network. A typical use case is to access Modbus devices, connect to older HVAC systems or in general any device that has a specific service. Many of our industrial customers use this to route specific PLC configuration protocols through the secure tunnel to their local machine. Then they use the vendor configuration tool, make it listen on localhost and the mapped port number and then they can work as if they are directly connected to that PLC.

In order to be able to do port forwarding you need to have created a public/private key pair on your local machine. The public key has to be distributed to the edge device. This can be done with the qbee ssh key function.

A more detailed description about how to achieve this can be found here.

So what are typical ports and services that qbee customer use?

VNC for remote desktop sharing

VNC is a remote desktop protocol. It is the abbreviation for Virtual Network Computing. It is a cross-platform screen sharing system that was created to remotely control another computer. This means that a computer’s screen, keyboard, and mouse can be used from a distance by a remote user from a secondary device as though they were sitting right in front of it. The standard port used for VNC is 5900, although this can vary. Mapping that specific port from a remote device allows you to remotely control that machine.

RDP or remote desktop protocol

RDP is a proprietary and Microsoft specific remote desktop protocol that allows you to remote control computers. While it is mainly used in Windows context there are clients available for Linux, Unix, macOS and others. By default, the server listens on TCP port 3389 or on the UDP port 3389.

HTTP and HTTPS

Any http port (usually 80) or https port (usually 443) can be forwarded. This is used to access HVAC systems, control systems or any other system that provides a standard user interface. A typical example could be a router or firewall.

Modbus

Modbus over TCP is a very popular protocol in industrial applications. The standard port for the TCP traffic is 502. This port can also be bridged to a localhost port on your local computer. While developing applications we observe often customers that map their Modbus box UI user interface to check that traffic is really ongoing. In addition they can feed the traffic directly in consuming applications for quick testing and prototyping.

MQTT

MQTT is often forwarded to cloud systems. In the early phase of an IoT development project this might only be available on a localhost port on the edge device. No problem with qbee. Just use the MQTT port (often default as 1883) and port forward it to your local machine to quickly get access to the data.

These are just a few examples how you can access any port on the edge with help of just one qbee device in the network.