LAN Game

Unfortunately, CS2 requires Steam authentication and doesn't support offline LAN play like the original CS:GO did. You'll need an internet connection and Steam accounts for all players. The old LAN functionality was removed when CS2 replaced CS:GO.

CS2 unfortunately removed the true offline LAN functionality that CS:GO had. The game now requires Steam's SDR (Steam Datagram Relay) certificates which can only be obtained through internet connection.However, there is a working workaround that many players use for LAN parties. You need to connect to the internet initially, join your LAN server while online, and then you can safely disconnect from the internet and continue playing over the local network. This method allows you to play locally once the initial authentication is complete.Some users have also mentioned using dedicated servers as an alternative solution. While it's not as convenient as the old CS:GO system, this workaround enables local play for LAN parties and similar scenarios where stable internet isn't available.

valve ruined everything once again smhcs2 is basically unplayable without internet because of their stupid "security" measures. they removed proper LAN support that worked perfectly fine in 1.6 and source for decades.only way to make it work: connect online first, join ur lan server, then disconnect internet. yes it's that dumb. or use dedicated server if u know how to set it up properly.valve keeps destroying everything that made CS great. miss the old days when you could just copy cs 1.6 to usb and play anywhere without steam bs :/