Problem with VPN on Android

[Ferrarista]

I disabled it, still the problem is there.

 

[Zastoff]

Is that a system setting? Where can I find it?

On my phone it is under settings network & Internet connection and advanced settings

edit:
also have "Advertise DNS to clients" set to yes under advanced settings on vpn server settings on the router

 

[pingu]

On my phone it is under Internet connection and advanced settings

Open your routers web interface
VPN -> VPN Server tab -> VPN Details - Advanced.
Compression is near the bottom. Set it to none.

 

[Ferrarista]

Open your routers web interface
VPN -> VPN Server tab -> VPN Details - Advanced.
Compression is near the bottom. Set it to none.

Great! This works!

Does it imply something in terms of performance/security? How come I was able to connect from my old Android 12 phone without changing the compression?

 

[pingu]

Great! This works!

Does it imply something in terms of performance/security? How come I was able to connect from my old Android 12 phone without changing the compression?

I don't know. I may be wrong but I have a vague recollection that turning on compression makes the encryption insecure so it's possible that the client refuses to work with it.
I tore some hair out before I found and tried changing this setting.

 

[Ferrarista]

Ok, this works, but it has huge implications: connection is now very slow and, most important, the geolocalization is now messed up. I need a VPN to localize myself out of the country where I am, and setting the compression to none makes a problem with this (on top of the connection that has become really slow)

 

[pingu]

On the server, with the VPN Details option set to 'general' is 'client will use VPN to access' set to 'both'?
On your client, with the VPN client running, use a web browser to navigate to whatsmyip.org and see if it returns the external IP address of your (router) VPN server.

 

[Zastoff]

Was/Are a security flaw with compression
And it was a recommendation to disable it and clients had warning's when using it maybe they changed in the client not to allow it anymore (could probably be changed in advanced settings in the client)

 

[Ferrarista]

On the server, with the VPN Details option set to 'general' is 'client will use VPN to access' set to 'both'?
On your client, with the VPN client running, use a web browser to navigate to whatsmyip.org and see if it returns the external IP address of your (router) VPN server.

With compression set to None, the returned IP is my local one (and not the remote one). I've also noticed that many services fail to connect to the internet (Dropbox, Onedrive, E-mail client).

 

[Ferrarista]

Ok, i have now allowed full compression for the client on the OpenVPN app and it works. Is there a reason why compression is deprecated?

 

[Zastoff]

Ok, i have now allowed full compression for the client on the OpenVPN app and it works. Is there a reason why compression is deprecated?

https://community.openvpn.net/openvpn/wiki/Compression

 

[Ferrarista]

Ok, I had not considered replacing the config file after disabling the VPN compression. Now I've disabled the compression and generated a new config file, works perfectly on both my laptop and my phone.
BTW what is to be preferred between Disabled and None (I'm talking of the compression)?