VPN L2TP not stable

[muelli75]

Hi!

Having here Ventura 13.0 and very much troubles with keeping a VPN-Connection stable (route whole traffic through the tunnel).

Connecting to our VPN (Ubiquity UniFi Network Application 7.2.95) is quick and OK.
Downloading data and files after connection ist quick and OK.
But uploading data to our server (QNAP TVS663), to another macs or upload files to a webinterface breaks the connection.

The tunnel keeps still established, but no data comes through the interface.

Sometimes it works for 4 to 10 MB, but mostly it breaks after 5 MB.

I can check this by ping to, for example, google.com
The ping keeps answering if I only download, if I start sending data through the tunnel, the stream stalls (see attached screenshot).

After some time the tunnel also collapses.

This happens after upgrading to Ventura, Montery kept the connection the whole day stable.


Do you have any ideas how to fix this very annoying behavior? Thanks for any hint!

 

[muelli75]

After trying several things for hours on the client side and on the server side - here is another hint.

On the server I set explicit to use the "Virtual Tunneling Protocol (VTP)" instead of L2TP for my connection. I had to change this in the Radius-Server-Section in the Unify-GUI. Now this seems to work better - but not stable at all.