Frequently Asked Questions
Additional support resources
To find additional questions and answers, and/or to ask your own questions, see the PortImport Support Forum.
How do I use PortImport?
For a visual demonstration of the program's usage, click here.
Make sure you follow the below steps very carefully:
- Download it.
- If you downloaded the self-extracting file (.exe), then run it, otherwise, use your unzipping program to extract the files from the downloaded archive.
- There should be 2 extracted files: NetworkActiv-PortImport-Console-xxx and NetworkActiv-PortImport-Daemon-xxx . The Console component is where you configure port forwards and is the component that needs to be on a computer that can be accessed (at least on one TCP port number) from the other computer. The Daemon component is the component that makes the connection to the Console component and is to be run on the computer that is behind the firewall/gateway/router.
- Run the Console and make sure that the port is accessible from the other computer. This may require you to forward a TCP port in your router's configuration to the computer running the Console component.
- If you are not going to use the default port already entered for the session (at the mid-top of the Console component's user-interface), then change it to the port you will be using.
- Press the button titled Enable, located just to the right of the field for the session port.
- Run the Daemon component (on the computer that is behind the router/gateway/firewall) and enter the hostname/IP-address from where the computer running the Console component can be accessed. If you are not using the default port number configured in the Daemon (in Settings->Advanced), then append a colon ( : ) to the hostname/IP-address, followed by the port number that you will be using for the PortImport session.
- Press the Establish button on the Daemon component's user-interface. This will attempt to establish the PortImport session by connecting to port on the computer running the Console component configured as the session interface port. The status of the establishment can be seen just under the box where you entered the hostname/IP-address of the computer running the Console component.
- If the Console component is not currently configured to automatically accept session-requests, you will need to manually accept the session by pressing the Accept button on the Console component's user-interface. Note that this button is only available when the Daemon has successfully connected to the Console and the Console has not yet accepted the session-request.
- Once a session is established, you may proceed to create, edit, enable, and disable port forwarding operations (PFOs).
How do I forward a range of ports?
As of this moment (2007.November.25), there is no option available to automatically configure the forwarding of a range of ports in PortImport.
Rather than manually creating a PFO for each port in the range you would like to forward (by using the program's user-interface), you can edit the settings file (located with the executable and named the same) and copy-paste-and-modify the lines that pertain to the PFOs. This could save much time over doing it via the user-interface of the program.
Important note: Since this program uses one thread for each port being listened on (on the Console-side), since Windows generally only allows up to 2000 threads per process, and since it takes threads for the forwards to be connected to and used, it is probably not reasonable to exceed around 1900 actual PFOs enabled at a given time. Therefore, you can only forward a range of less than 2000 ports total. If your application wants more, then try looking into its configuration and see if you can make it use a smaller range.
Is NetworkActiv PortImport a Trojan horse?
A Trojan horse is a program or code fragment that carries out malicious tasks without the user's knowledge or consent. Specifically, if we consider where the word comes from in the first place, we see that the nature of a Trojan is to act as something other than oneself -- to deceive by putting on a false veneer.
Here are some examples of computer Trojans:
- A screensaver that secretly allows hackers to remote-control the computer while the visualisations are showing.
- A chat program that covertly allows the person on the other end to access your files.
- A free video game that when "closed" remains running in the background and allows remote users to execute system commands.
NetworkActiv PortImport does not meet the criteria for being a Trojan. Specifically note the following about its function:
- Both the back-end Daemon and the front-end Console run where the user can see them -- either in the task-bar or the system tray. The only hidden mode is while running as a system service, but installing system services requires administrative privileges.
- Neither component pretends to be something it is not.
- Both components show real-time, on-screen indicators of what is currently happening.
- Either component can be stopped immediately by clicking the "Close" button to terminate the session. Furthermore, either component can be stopped by going to File->Exit and choosing Exit or Force Exit.
- Neither component is capable of doing anything to the other computer beyond accessing TCP and UDP ports, resolving hostnames, and sending chat messages. Unlike SSH, VNC, Remote Desktop, and various other technologies, PortImport is not remote-control software, nor does it have any remote-control features. Many such remote-control packages out there also can run as system services if administrative privileges are available, but remote-control packages by their nature pose vastly greater of a security threat.
- Both components leave the user in full control of his or her computer. Absolutely no mechanisms are in place to control or limit control of the mouse, keyboard, or any other controls of the system.
In conclusion, many extremely common tools used by everyday administrators are closer to the definition of a Trojan horse and pose far more of a potential threat than NetworkActiv PortImport. Perhaps any tool -- even a screwdriver -- can be used maliciously. But not every tool should be ostracised as contraband.