Now I will write down in a minute how to get rid of the "closed / moderate" "NAT" and make it "open". The problem does not allow you to play ranked in forza or play normally in sessions, endless downloads appear and nothing further happens.

To check the type of NAT, click "search" on your taskbar and enter "xbox network", wait a bit and the type of NAT will appear. If it is open, you can stop reading the manual, everything is fine with you, but if it is closed or moderate, then you are at the right place.

To get started, find your IP by typing ipconfig into the command line (cmd in the search as administrator), copy the code for the main gateway and enter it into the search engine, you will be taken to the website of your router (the default login and password is user / user). Next, find the UPnP item and enable it. After that, go to NAT - DMZ host and enter the IPv4 address there (you can read more about what it is if you have doubts about the security of the method). Great, half the job is done, time to reroute the ports. Also, on the provider's website, go to Port Triggering and write these ports there https://portforward.com/forza-horizon-4/ (for steam), write the same ports in Virtual Servers. Turn on the firewall on the PC, if it is turned off, and the Windows defender (without this, in any way)

Go back to cmd and enter the following commands in order:
1) netsh interface Teredo set state type=default
2) reg add HKLM\System\CurrentControlSet\Services\Tcpip6\Parameters /v DisabledComponents /t REG_DWORD /d 0x0
press Y
3) netsh interface Teredo show state

Next, press Win + R and type gpedit.msc, then go along the path "PC Configuration - Administrative Templates - Network - TCP / IP Settings - Tunneling Technologies for IP version 6", go to "set teredo client port - enabled, port 3544" / "set default teredo qualification - enabled - enabled state" / "set teredo refresh rate - enabled - 2 sec" / "set teredo server name - enabled - server name win1807.ipv6.microsoft.com" / "set teredo state - included - corporate client". Do not forget to press after that first apply, then OK

Now the type of your NAT is moderate, which won’t allow you to get into the rating anyway, just for fun, right?)

To make it open, you need to connect to the network via a patch cord (it costs a penny in dns), only in this case you will open NAT, thanks to the developers for the clumsy work of the game in steam

Please, like the guide, I think it will help many, because there is no information on the Internet from the word at all