Once you install CentOS 7, by default firewalld will block almost all network traffic.

In order to open ports for certain services you can easily reconfigure firewall using firewall-cmd command.

[root@localhost firewalld]# firewall-cmd --get-active-zones
  interfaces: eno16777728
[root@localhost firewalld]# firewall-cmd --zone=public --add-port=80/tcp --permanent
[root@localhost firewalld]# firewall-cmd --reload

Example contains port 80, however you can open any port using same method.
It is worth to check zones configured on your machine and make sure you open port in proper zone where service should be enabled.