other people cant log in..

ok my server is up and running, now one of my friends wants to join it but i havent really done the website..soo i made him an account and i made it a gm... and i can connect perfectly fine but for him it says connecting..then disconnected from server

oki if you have a dynamic ip and used a no-p then you need to update your no ip add whit this tool , you only need to log in with it , (your no-ip acount ) and your done , , remember only if you have a no-ip addres