NFS servers and firewalld

This should be enough:

firewall-cmd --permanent --add-service=nfs
firewall-cmd --permanent --add-service=mountd
firewall-cmd --permanent --add-service=rpc-bind
firewall-cmd --reload

After configuring NFS server we should enable and start three services:

1. nfs-server.service
2. rpcbind.service
3. nfs-mountd.service (only start is needed)

And also allow these services on server firewall:

# firewall-cmd --permanent --add-service=nfs
# firewall-cmd --permanent --add-service=rpcbind
# firewall-cmd --permanent --add-service=mountd
# firewall-cmd --reload

Just found this - and it works when the problem is SELinux blocking the reading of the ~/.ssh/authorized_keys during login! First, enxure your ~/.ssh/authorized_keys file is properly populated and its permissions and its folder's permissions are set correctly. If you then run "setenforce 0" on the SSH destination host and are able to login to that host without entering a password, but cannot do so after entering "setenforce 1" on that same destination host, the following may fix your issue:

setsebool -P use_nfs_home_dirs 1

ref: https://cassjohnston.wordpress.com/2015/06/12/selinux-nfs-home-directories/