Have a problem server online when connect from internet

I can login, play game when i login from i computer
other computer i can login but can't choose chanel (connect fail)
i opened port 31000 -39000
i change ip internal.txt serverlist.txt
i have a no-ip host and noip-client
in centos i can ping google.com
in my computer i can ping centos
help me.
sr my en so bad...

Do you connect to the no-ip host as well. Remember that if you change the ip on the server all the clients need to use the same ip, that includes you.