How do I debug why the connection is not coming up?
I can ping from outside.
I have just gotten a fibre connection from fibia.dk, with a static IP, and passthrough the fibremodem, but the tunnel doesn't connect.
I also have a 4G from 3.dk, if I use that as endpoint, then the tunnel works, but it is way slower, and metered, so I don't want to use that.
So if one works and the other doesn't, we have to look at what's different between the two setups
The difference is that the one that works is a 4G mobile connection while the other is over fibre from another company.
If I should have any chance of this getting to work at a company, who doesn't even have any plans for IPv6, to understand, I need something like a traceroute from the HE gateway saying "The GRE packets are being dropped at this ip"
I have two VPS servers on the outside with IPv6-connectivity I can use to check if needed.
Oh, I found the error.
When I changed the endpoint address on HE, I didn't change the interface on my PfSense on which the GIF tunnel ended on.
I fixed it; I made a second tunnel on the same HE endpoint, so I now have two tunnels, one over fibre, one over 4G mobile network.