[root@<server> ~]# firewall-cmd --list-all
internal (default, active)
  interfaces: enp5s0
  sources: 192.168.10.0/24
  services: dhcpv6-client ipp-client mdns ssh
  ports: 2049/tcp
  masquerade: no
  forward-ports:
  rich rules:

[root@<server> ~]# showmount -e localhost
Export list for localhost:
/export/home/<user> *.localdomain

[root@<client> ~]# showmount -e <server>.localdomain
clnt_create: RPC: Port mapper failure - Unable to receive: errno 113 (No route to host)

[root@<server> ~]# systemctl stop firewalld

[root@<client> ~]# showmount -e <server>.localdomain
Export list for <server>.localdomain:
/export/home/<server> *.localdomain

[root@<server> ~]# systemctl start firewalld

[root@<client> ~]# showmount -e <server>.localdomain
clnt_create: RPC: Port mapper failure - Unable to receive: errno 113 (No route to host)

[root@ ~]# firewall-cmd
>  --add-port=111/tcp
>  --add-port=111/udp
>  --add-port=892/tcp
>  --add-port=892/udp
>  --add-port=875/tcp
>  --add-port=875/udp
>  --add-port=662/tcp
>  --add-port=662/udp
>  --add-port=32769/udp
>  --add-port=32803/tcp
success

[root@<server> ~]# firewall-cmd
>  --add-port=111/tcp
>  --add-port=111/udp
>  --add-port=892/tcp
>  --add-port=892/udp
>  --add-port=875/tcp
>  --add-port=875/udp
>  --add-port=662/tcp
>  --add-port=662/udp
>  --add-port=32769/udp
>  --add-port=32803/tcp
>  --permanent
success

[root@<server> ~]# firewall-cmd --list-all
internal (default, active)
  interfaces: enp5s0
  sources: 192.168.0.0/24
  services: dhcpv6-client ipp-client mdns ssh
  ports: 32803/tcp 662/udp 662/tcp 111/udp 875/udp 32769/udp 875/tcp 892/udp 2049/tcp 892/tcp 111/tcp
  masquerade: no
  forward-ports:
  rich rules:

[root@<client> ~]# showmount -e <server>.localdomain
rpc mount export: RPC: Unable to receive; errno = No route to host

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

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