Why does VPN have to be disabled for the 4STREAM app to work?

Why does VPN have to be disabled for the 4STREAM app to work?

4STREAM cannot wifi connect to new devices or find my successfully connected wifi devices when basic privacy VPN is enabled. If these devices are communicating on my LAN, I can’t imagine why WAN/public IP would be relevant (unless the software is communicating to external servers). What data is being shared over WAN during/after connection? Seems like a potential privacy concern.

Thanks

New Customer

#VPN #privacy #4STREAM #LAN #WAN

@TexasAudio if you connect to a vpn network with your phone, the device is in a different address range than the arylic devices on the LAN, so the launched 4stream app cannot find them, so on the vpn server, routing between the vpn and real lan address ranges must be set up (enabled).

@zitev With all due respect, that’s not how VPN’s work. If the VPN client on my phone changed the phone’s local IP then the phone would lose all network connectivity, thus rendering everything inoperable. In fact, every VPN in the world would be fundamentally broken if it worked that way.

If you want an example, connect your phone and arylic to your home wifi, enable phone VPN, then try to connect to your Arylic device (or any device on your LAN) by opening the phone’s browser and navigating to http://DEVICE_IP. As long as the device is taking http requests, the connection will be successful because both your phone and the device are on the same LAN subnet. The fact that the VPN is enabled has no bearing whatsoever, because the phone is the client and the device is the server and both are on the same subnet.

On the other hand, public servers (i.e. servers on the WAN, aka servers on the internet) are on public subnet and would see client requests coming from a public IP. If your phone VPN is disabled, the public server would see the request coming from your modem’s public IP (provided by your ISP). If the phone VPN is enabled, the public server would see requests coming from your VPN provider’s public IP. If the public server allows your modem IP but does not allow your VPN IP, then you would see things break when you enabled/disabled the phone’s VPN client. But, no matter what you do, your LAN IP does not change, and the public server has no idea what your LAN IP is, because it’s completely irrelevant.

So, again, why is 4STREAM acting like a public server and using a public/WAN IP to function? It may be completely innocent, but it’s important to understand for troubleshooting and for privacy.

The app is on my phone, which should ideally act like the server on my LAN. When the client (arylic device) and server (4STREAM on my phone) are on the same subnet they should be able to communicate with one another. However, when a VPN is on, the public IP changes (the local IP stays the same) and 4STREAM breaks. The only logical reasoning behind this is that the 4STREAM server is actually centralized outside my local network, and it is taking requests, gathering data, and serving data ACROSS THE WEB. Moreover, it would break if my internet went down! Why would that be?

Thanks

*Edited for clarity and tone

@TexasAudio Ok, just briefly. Connect via wifi to your own subnet shared with the arylic devices and turn off the vpn on the phone! Pull out the internet cable from the router, then start the 4stream app! If you see all your arylic tools the same, then clearly what you claim is not happening!

@Zitev LAN’s function without the internet. You clearly don’t understand networking so please ignore this thread if you aren’t going to be helpful.

Does an IT professional or someone who understands networking know more about the 4STREAM app?

Thanks

@TexasAudio lol, ok, wish you good luck!..

@TexasAudio

I think you misunderstand how a VPN work. Basically what a VPN does is that all traffic from your device will be sent first to the VPN server, than the VPN server will send your request to the final IP address, receive the response in your place and forward it back to you. This is a simplified view as there are multiple protocol and I don’t know all of them by heart.

What you must remember from this, is that your phone is not connecting to anything directly anymore, it goes first through the VPN server (it also apply if you are using a proxy or a reverse proxy for all traffic).
So if your local address is not exposed on the web, it is not visible from the VPN server. That is why your streamer does not work on LAN with your phone anymore.

From there there are two options to solve the issue :

  1. You use a split mode of some sort (allow a particular app not to use the VPN for instance 4Stream app). I would chose this one if you are using VPN for localisation purpose (streaming, scholar search, etc).
  2. You configure the VPN at your home router level and disable it for all device into that subnet. That way only traffic toward outside your local network will be impacted. I would choose this one if you primary use VPN for your privacy as it guarantee that all traffic goes through your VPN even for device which are not compatible (most connected devices like old smart TV (not android), streamer, amplifier, ip camera, etc, etc does not support VPN apps so configuring your router is the only way to guarantee you use your VPN for all communication going out of your LAN)

As a side note, the reason you can connect in your browser is probably because you activated an option called “discover local network device” or something in your VPN app. This will indeed work for some devices but it is no guarantee it will work with all protocol and apps, sending you back to one of the two option above.

Ah! Ok nevermind… I’m an idiot. Thank you both for helping me realize I was barking up the wrong tree. You’re right that LAN communication via browser was working only because I had an app exception for the mobile browser. Ultimately, I was not factoring in the ENCRYPTION piece of the VPN, which is what is actually breaking LAN communication between app and device (it has nothing to do with external servers or subnetting/IP at all).

Regards