DNS Configurations - Public - Services don't work

Hi,

I've been running some gameservers on an Azure Virtual Machine and the games i play use a master list where the gameservers are added. I've opened up port 53 for the DNS, and all the ports the gameserver needs but still it complains that the DNS name could not be resolved for the ip address. 

If i check the set-up of the server i've got my name.cloudapp.net DNS name, but i don't know what this means..

What do I have to do? Set up a DNS in the server itself or...? Can anyone shed some light?

Thanks