Does netmaker need internet access? I mean can i use it a totally closed network where none of the node has internet access? how does the EE license key and other EE part will work?

EE will not function without internet access currently. Community should function locally as long as everything is configured correctly. However, in future iterations having access to the internet will be a lot better in order for the server to properly diagnose your client's NAT type. It is still possible if you host at least 1 stun server yourself on that local network though (+ the NM server).

unfortunately we need to use a solution in a totally closed net environment (ie all net access is firewalled from these nodes). So all of the netmaker components should have to be run inside this network arch. or it's not a solution for us...