Linux Open Ports

It is important to note that the firewall is managed by iptables in CentOS 6 and the firewall is managed by FIREWALLD in CentOS 7.

1. In CentOS 7

Use the following command

Firewall-cmd [--zone=<zone>]--add-port=<port>[-<port>]/<protocol> [--timeout=<seconds ;]

As an example,

Firewall-cmd--zone=public--add-port=8080/tcp--permanent

Explain:

--zone Scope

--ADD-PROT=8080/TCP Port/Communication protocol

--permanent is permanently active and will not expire if this parameter is not restarted

Executing the command prompt success indicates that the add succeeds, at this point if the query will find that port 8080 is not released because the firewall needs to be restarted

2. In CentOS 6:

If you are accustomed to iptables, you can also install Iptables-service in CentOS 7

Yum Install iptables-Services#  set boot systemctl enable iptables

Also take open 8080 port as an example

Execute vim /etc/sysconfig/iptables command

Add in File

-A input-p tcp-m state–state new-m tcp–dport 8080-j ACCEPT

Restart Iptables When you are finished modifying

Service Iptables Restart

Execute iptables-l command to view firewall rules

Linux Open Ports