got an idea, that d-link old router wich i had lying around.. does heave a firewall and a dmz (if you understand it here i woud be great but if not, read furter
so i just dmz that router in the sitecom router and use the build in firewall n the d-link router and then i dmz the Centos server in the d-ink router zo it cou communicate totaly with the free worl and the other network members (like the minecraft server) so it wou look like this,
https://creately.com/diagram/ijr6isp81/uslrzpHfscJLQ8ZYJoUDXGJgcs%3D