Our solution for DCs problem

[AISguy]

I haven't yet found if my router supports hairpinning, but I've found that my public IP differs from the IP that the provider gave me.
IP on the WAN port of my router is 192.168.20.130;
My current public IP is 212.45.15.98

It's said (paragraph 3) https://help.keenetic.net/hc/ru/articles/115002886909 that in this case (provider NAT) the port forwarding is impossible.
Did I understand my situation correctly?
Did anyone encounter situations like this?

EDIT: I checked it. We have hairpinning.

[PhilipJFry]

not sure but some people who cannot map a port for the game (e.g. cause they don't have access to their router) use a vpn which seems to work reasonably well

this would also help with 2 users on the same local network since both could use different vpn addresses and thus circumvent the issue of having to map 2 ports on 2 different local addresses

[AISguy]

use a vpn

Did they forward ports during VPN?

[AISguy]

Today we tried:

1. Disabled UPnP on the router, not only in FAF - didn't help (~10min DC).
2. Just to check, with (1.), disabled NAT on the router - the internet went down.
3. We mentioned that in logs, some ports (the "info: LOBBY: Game port %%[UDP] opened." string) were kind of different (6113 for my friend and 6112 for me). We tried to forward them - didn't help (DC after 1h30min).
4. Proton VPN without UPnP in FAF and in router - didn't help.

5. Proton VPN with UPnP enabled in FAF and in router - we managed to play a full campaign game with a couple of desync warnings (1h40min). We had some freezes, but no DC screens.

Throughout all these attempts we didn't manage to forward ports.
I don't know if (5.) is luck or the solution. We will play more tomorrow.
The logs have full info about the last successful game a some info about today's previous failed games.

[AISguy]

Checked today. The DCs are still there.
We tried to play a match and experienced a 11sec DC which was not fatal, but the second one lasted more than 50sec, so we stopped the game. Seems like VPN without port forwarding doesn't do the trick.

The thing that we didn't try yet is a VPN with port forwarding, but I haven't found a free VPN with this option yet.

[MobiusBE]

Hey AISguy

Just pitching in here... Have you tried turning off IPv6 in your network adapter settings?
uPNP would not work with IPv6 enabled for some unknown reason for me (although all settings seemed fine). It started working fine when I switched to IPv4 only. (topic here)
Try turning off IPv6 in your adapter settings, enable uPNP and remove manual port forwards.
This did the trick for me. You never know...

[AISguy]

Try turning off IPv6 in your adapter settings, enable uPNP and remove manual port forwards.

OK, this plus VPN, or without VPN?

[Uveso]

if i am not wrong, the error description was:
"we always had disconnections (DCs) after some time"

This can't be related to portforwarding.

You need Portforwarding (manuall or with UPnP) to get a connection to other players.
If you have this connection and you can start a game, then your router knows how to route the data.

You router will not forget how it has to route the data while you play.
So if you get a disconnect, this is not related to portforwarding

If course i can be wrong, but i don't think its your router thats causing the problems.
At least its not portforwarding.

[MobiusBE]

Try turning off IPv6 in your adapter settings, enable uPNP and remove manual port forwards.

OK, this plus VPN, or without VPN?

Without.
But....

if i am not wrong, the error description was:
"we always had disconnections (DCs) after some time"

This can't be related to portforwarding.

You need Portforwarding (manuall or with UPnP) to get a connection to other players.
If you have this connection and you can start a game, then your router knows how to route the data.

You router will not forget how it has to route the data while you play.
So if you get a disconnect, this is not related to portforwarding

If course i can be wrong, but i don't think its your router thats causing the problems.
At least its not portforwarding.

Yeah this might be accurate.. My problem wasn't losing connection in game, but rather not getting a connection in the lobby.
So I guess Uveso is right . Sorry...

[AISguy]

Uveso, MobiusBE, thank you for your thoughts.
Yeah, our problem is in getting DCs after some time in the match/mission.
Once we even got a non-fatal DC during the FA Red Flag starting cutscene (water mission).
The longest non-fatal DC throughout all our attempts was 11 seconds.