[Memphiz]

AFAIK NFS doesn't support a username/password approach at all, unlike SMB.

While completly offtopic here imo i just want to tell you that NFS auth is not only based on ip. The IPs/subnets you are putting in /etc/exports only tell the server which clients are allowed to connect. Connecting is the first step but not the final one. After connecting the real read/write permissions are determined based on the uid (user id) of the connecting client. This userid is either remapped to an uid on the nfs server or the same uid has to exist on the server. Based on that uid and the normal linux/unix file system permissions nfs determines if a user can read or write or not even see anything.

So yes - no username/password, but no - its not only the granted ip range.

/offtopic.