@viragomann
So I just took another look and I think I can confirm that the packets do go back over the ISP network (because I see that the packets try to go through my ONT in both directions) - thanks
Yes, I noticed this and it's quite strange to me. I'd had ideas for reasons if it would behave the other way round.
The main reason why I tried TCP in the first place was because I saw this post on serverfault.
I don't think the scenario is quite the same, but it's the only thing I've found on the internet that had any semblance to my issue (where the port #s change):
65d9f08d-212c-4fea-907e-4511765fc9a7-image.png
Since you don't provide IP addresses, I'm missing the needed information to investigate.
Here's the previous packet capture of when I tried to connect to the VPN server from within the ISP network (where pfSense WAN IP is 50.x.x.x, the ISP WAN IP is 75.x.x..x):
0b611736-20e8-4962-833d-87b604ed0e08-image.png
And here's the packet capture when I connect to the VPN server from an external network (where 207.x.x.x is the IP of the external network):
3db70683-6491-4481-920d-ba53f95243d0-image.png