There are several different ways to use IPTABLES in Centos. You can turn off the host -based firewall, or configure PTABLES to open the port. Using IPTABLES is a good choice for those who need to communicate with other hosts, but do not want to take the risk of allowing traffic that is not trusted through their firewalls. This requires knowledge about the network, and the example displayed here is a simplified version.

Centos Firewall PTables uses a policy chain to manage traffic. When the connection tries to build, he looks for rules in the policy chain. If not, he uses the default action. The incoming connection uses the front chain, which is used when they are not sent locally. Many protocols require two -way communication. To allow this type of traffic, you must modify your firewall configuration file.

Iptables centos open port is a Default Centos firewall. It works with a policy chain to enable traffic and drop the incoming connection if it does not comply with any rules. When the connection tries to make a connection, IPTABLES searches the rules in the list, or resort to the default action. When the incoming connection does not have a local address, he uses the front chain instead. The incoming connection that does not reach the local network is dropped unless you tell them.