Allow NNTP through CentOS7 firewalld

How to Allow Network News Transfer Protocol (NNTP) on CentOS7 (firewalld)

If you want to run an NNTP server on CentOS7, you will need to add a service definition for the firewall, and then allow the traffic.

# cd /etc/firewalld/services
# vi nntp.xml
<?xml version="1.0" encoding="utf-8"?>
 <service>
 <short>NNTP</short>
 <description>Network News Transport Protocol</description>
 <port protocol="tcp" port="119"/>
 </service>
# firewall-cmd --reload

Practice adding the service -- adjust the zone as needed:

#firewall-cmd --zone=internal --add-service=nntp

Permanently add the NNTP traffic allowance:

#firewall-cmd --permanent --zone=internal --add-service=nntp