Hi chroniac,
to host a server without hamachi you need "DynDNS" or a root server, on which you can install any server operating system (you may use FreeBSD for your Hamachi server). To host a metin2 server u have to rent a root server. If you don't want to pay you can also host a server on your own computer, and bring it online via DynDNS or Hamachi. But, be warned: If you rent a root server in europe it is easy for the metin2 publisher Gameforge 4D to locate your position, and then you may get a threnodial, so I would not recommend to do this. If you want to be sure that your almost safe, you should rent a server which is not located in Europe. On YouTube you will find many tutorials how to host a server via DynDNS or Hamachi, so that shouldn't be the problem.
Best regards,
Yusago™