I am attempting to start a Windows LAN game with a Linux Mint computer that is taken off the Internet by not specifying a gateway address. The game is Warcraft III a pre-Reforged version, aka Warcraft III: The Frozen Throne.

The reason I am doing this is that I am preparing for the day that I have to use this Mint computer without Internet access on... whatever, don't ask.

The symptom is that the Mint computer would not see the games created by the Windows computer. Before taking out the gateway, the Mint computer would see it, after taking out the gateway, not so.

I know that LAN games will run without gateway addresses as gateways only serve their purposes by linking computers in its network to computers outside it, so I know taking out the gateway is not the cause of the problem itself, and taking out the gateway address only severs the connection between the computer and computers outside the network.

At the same time, that's the problem.

I do have Virtualbox installed, and I am trying to find the Host-only adaptor for it. On a Windows machine, which was also taken offline, the only way I can LAN game that machine to another machine in the network was to disable the Host-only Adaptor in the network settings. I can't find that in the Mint computer.

Does anyone know of a way that I can play a Warcraft III TFT game with the Mint computer without a gateway specified, like playing it without an Internet connection?

EDIT: I will add that I can use the network without the Gateway specified, and ping to it, but I just can't access the Internet as was intended.

What OS runs as a VirtualBox guest? A host only adapter only allows a host to communicate with a VM as well VM to VM.
Is the gateway still active but just not connected to the internet or is it removed completely? Do you also have a switch connecting the computers together?

Typically computers are configured using DHCP to assign IP addresses so removing the gateway entirely will require each computer to be configured using static IP addresses. If the computers are also configured to use APIPA then they will automatically be assigned an IP address in the range of 169.254.0.0 to 169.254.255.255.

Does each computer have the save version of the game? Does the firewall on the windows computer allow incoming connections for the game app. Is the Windows computer network adapter configured for a private LAN. I do not know what port it runs but you need to configure that for the linux computers if running a firewall or on a standalone network just turn it off.

Are you using wine on the Mint computer to run Warcraft? Have you tried setting up the LAN game on the Windows computer and seeing if Mint can see the game?