RHEL7: Firewalld

firewall-cmd --list-all-zones
firewall-cmd --get-active-zones
firewall-cmd --info-zone=public

firewall-cmd --permanent --new-zone testZ
firewall-cmd --permanent --zone=testZ --add-source=192.168.43.0/24
firewall-cmd --permanent --zone=testZ --add-source=192.168.31.0/24
firewall-cmd --permanent --zone=testZ --add-service={ssh,http,https}
firewall-cmd --reload
firewall-cmd --info-zone=testZ

firewall-cmd --permanent --zone=trusted --remove-source=192.168.31.0/24
firewall-cmd --permanent --zone=trusted --remove-service={smtp,dns}

firewall-cmd --zone=public --add-interface=ens160

firewall-cmd --get-services

MySQL user with ip range

For a host value specified as an IPv4 address, a netmask can be given to indicate how many address bits to use for the network number. Netmask notation cannot be used for IPv6 addresses.
The syntax is host_ip/netmask. For example:

CREATE USER 'david'@'192.58.197.0/255.255.255.0';

https://dev.mysql.com/doc/refman/5.6/en/account-names.html

config apaceh ssllabs A+

SSLEngine on
SSLProtocol TLSv1.2
SSLCipherSuite HIGH:!aNULL:!MD5:!EDH:!3DES:!CAMELLIA:!AES128
SSLHonorCipherOrder on
Header always set Strict-Transport-Security "max-age=31536000"