Ip Not Working

Well i can get my server online but, i need to use the Dyn Ip which will always change and i need a way that i can have an ip or something that wont change whenever i start my server so my friends can get on easier. When i tried to use the ip (not dyn ip) it will say java.net.ConnectException: Connection timed out: no further information: And im running on crack. im using win 8.1 pro but when i tried with win 7 it also fails. Im also running on 1.7.9 craftbukkit. and remember that if i use the dyn ip it will work but it will always change so it will be hard for my friends to join. And one more thing, how can i change my server name for authme. THX

Oh, sorry for me being not clear about it but, there is a plugin called authme and it says my server name is unknown server server