On the server I installed nfs-kernel-server as I read about some problems with the user mode server. From the old day's I still remember the files used to configure the server.
- /etc/exports: /dir ip(rw)
- /etc/hosts.allow: ALL:ip
- /etc/hosts.deny: ALL:ALL
This didn't work. Access was denied. The access is controlled by the user and group ID. All users are created separately and not controlled by NIS or LDAP server. The quick solution is to map all access to the local user with anonuid and anongid.
Still not able to connect from the Mac. The user access is granted by the server. The Mac connects with a port number greater than 1024. Therefore insecure is needed.
Help was the nfs howto and this thread about mounting nfs on Mac.
TODO: look into the command exportfs to manipulate the NFS exported file systems.