Some NO-GO Situations

Applies to : FGC (+ FGU in LAN mode)

Unfortunately there are situations where you can't break some of barriers 4 to 6 "as is". Some common ones are listed below. Most of them come down to the inability to have the proper port forwarding rule applied on at least one NAT/PAT router between you and the Internet.

No unique IPv4 public address per subscriber ("IPv6 Internet connection")

Some ISPs and countries rely on a purely IPv6 infrastructure, down to the subscriber endpoint. In that case they already use a form of NAT/PAT in the ISP network to share a public IPv4 address between multiple subscribers.

In this situation, there is no way to have a port forwarding rule applied, for one specific subscriber, within the ISP network infrastructure itself.

That is a NO-GO for FG "Classic" game hosting.

No administrative acces to an "Internet router(s)"

In case you cannot acces the administration/setup facility of one or more of the NAT/PAT routers between you and the Internet :

You will then be unable to apply a port forwarding rule in that router, so...bad luck !

Public/shared Internet access

Sometimes if you are a "GM on the road", you'll need to use a kind of public/shared access to the Internet (hotel room, internet cafe, cell phone internet access, etc...), which means that here also you will not have admin access to the NAT/PAT router, and once again :

You will be unable to apply a port forwarding rule in that router, so...bad luck !

Upstream "closed" firewall

You may not always be able to "open ports" or add "exceptions" on the firewalls between your GM FG program and the Internet, even if proper port forwarding rules have been setup. This is generally true when you are in a protected/corporate network environment.

If a firewall you don't control blocks incoming connections to TCP 1802, it's also a NO-GO for FG "Classic" game hosting.