L2TP issue on Ventura?
I had been using macOS Big Sur with two L2TP VPN configurations with no problems.
I have now built a fresh laptop running macOS Ventura 13.0.1 and having problems with one of these VPN configurations.
Both configurations are for connecting to devices acting as L2TP servers, one is a Draytek ADSL router and one is a SonicWALL Firewall.
I can successfully connect to the Draytek router, this being both the ADSL router and the VPN server does not have the VPN server behind a NAT gateway. The SonicWALL at a different site is however behind another ADSL router which is performing NAT. In this second case the ADSL router doing the NAT has been configured to forward all the L2TP required ports to the SonicWALL. This works fine with older versions of macOS!
It is apparently not working with macOS Ventura 13.0.1
I am therefore wondering if macOS Ventura has broken the ability to traverse NAT?
Note: The error message I get is very basic as below
Tue Dec 6 17:22:31 2022 : IPSec connection started
Tue Dec 6 17:22:31 2022 : IPSec phase 1 client started
Tue Dec 6 17:22:31 2022 : IPSec phase 1 server replied
Tue Dec 6 17:23:01 2022 : IPSec connection failed
Or if you prefer the GUI
MacBook Pro