1. [root@prod-stage-nfs-server ~]# systemctl restart firewalld.service 
    2. [root@prod-stage-nfs-server ~]# firewall-cmd --permanent --add-service={nfs,nfs3,rpc-bind,mountd}
    3. Warning: INVALID_SERVICE: 'nfs3' not among existing services
    4. success
    5. [root@prod-stage-nfs-server ~]# firewall-cmd --reload 
    6. success
    7. [root@prod-stage-nfs-server ~]# firewall-cmd --list-all
    8. public (active)
    9.   target: default
    10.   icmp-block-inversion: no
    11.   interfaces: eth0
    12.   sources: 
    13.   services: ssh dhcpv6-client nfs rpc-bind mountd
    14.   ports: 
    15.   protocols: 
    16.   masquerade: no
    17.   forward-ports: 
    18.   source-ports: 
    19.   icmp-blocks: 
    20.   rich rules: 
    22. [root@prod-stage-nfs-server ~]#

    https://www.cnblogs.com/BloodZero/p/4783578.html

    1. echo 'mountd:10.82.100.108' >> /etc/hosts.allow
    1. echo 'mountd:all' >> /etc/hosts.deny