High Security Relevance
This setting is important for the security of your server!
Use it carefully! Wrong settings may make your server vulnerable or limit its functionality or accessibility!
Set the maximum number of clients with the same IP which are allowed to be at the server simultaneously. This setting is a protection against attacks which work by joining with several clients (which are idle/fake) at the same time to fill a server and making it useless for real players that way (either by filling up all slots or by destroying game play with idle players or random/destructive player actions).
Attention: Set it to a low value (like 1) if you experience attacks with (fake) clients.
Attention: Set it to a high value (32) for LAN servers. Otherwise it may block people from your own LAN from joining your server.