Multiplayer

Satisfactory can be played in Multiplayer, with up to 4 players officially supported, but with no hard player-limit. The game is coop only and there will be no PvP elements. Currently, there are no dedicated servers, meaning that servers are hosted on the machine of one of the players, while they are playing. But there are plans to add them, most likely post-alpha. As of February 2019, Multiplayer is in the alpha.

In order for more than 4 players to be able to play in one session simultaneously, the game's config has to be edited.

Server Options
When hosting a multiplayer server you can choose the following settings:

Privacy
There are no plans for a "Public" option, due to griefing concerns.
 * Friends - Anyone on your friends' list can join your game without invitation
 * Private - Players can only join your server if sent an invite.

Network Ports
While network configuration shouldn't be necessary, you may open these ports to aid in troubleshooting network connections.
 * 5222 TCP & UDP
 * 6666 TCP & UDP

Also, make sure you didn't accidentally refuse the Windows firewall rules.