How to deny access to SSH?

Question

linux

Just discovered log feature in linux server...saw a bunch of connections per second from different IPs trying to login but wrong password. I would like to restrict access to only one IP. But there is a game server on the server and I don’t know how to do it right, because I can block access to players

Answer 1

1) move ssh to another port
2) configure key
authorization 3) install fail2ban
4) configure iptables (not recommended for beginners ) step 4
will allow you to leave only game ports and ssh open for access, and protect ssh step 1-3

Answer 2

iptables ssh from specific ip

Answer 3

Set up a key-only connection. All password pickers will immediately break off
https://netpoint-dc.com/blog/nastrojka-autentifika...

Answer 4

port knocking

Answer 5

Port 22/1022 block. How convenient through a router or through iptables.