[SOLVED (problem, not debugging)] Debugging no connection

[leifnel]

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.

[cholzhauer]

So if one works and the other doesn't,  we have to look at what's different between the two setups

[leifnel]

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"

[leifnel]

I have two VPS servers on the outside with IPv6-connectivity I can use to check if needed.

[leifnel]

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.