Hi, i have ban system by cid, ip, name but players change name, ip and cid. How else i can ban a player?
You can't, it's simple not possible. If you're thinking how the Java servers do it, it's because no one wants to pay $25 to buy a new account only to ban-evade.
Most people don't bypass bans by using a VPN. Most of the time, they just wait for their ISP to give them a new IP address. No VPN required. Everything else can be changed even easier.
Or purchase 1(+)k alts starting at 99 cents! But the point should be self-evident, no matter what you put: VPN blocker, proxy, etc. There will always be a way to bypass such b̶a̶r̶r̶i̶e̶r̶. All we can do is slightly decrease the possibilities!
Isn't there any way to get the Clients Devices Identification Number or something that defines the device? So you can ban that ident
Well, no. Do you mean the client ID? That identifies the player's game client. It's easily changeable, by editing a simple text file in the game's folder.
Anything sent by the client can be changed via a mod. The only thing the client can't easily change is the IP address because it needs to be correct to send back data correctly, but there are workarounds already, too . It's like receiving a scam (physical) mail. The sender can lie about everything they write ("hey I am Koko's ghost"), except the sender's address must not be fake, because otherwise they can't receive your reply.