Allow OpenVPN Through a Port on CentOS 6.5: Simple Guide

To allow OpenVPN traffic through a specific port on CentOS 6.5, you’ll need to configure the firewall to permit traffic on the port used by OpenVPN. CentOS 6.5 uses iptables for firewall management. Here’s a step-by-step guide on how to do this:

1. Determine the Port Used by OpenVPN

First, you need to know which port OpenVPN is using. By default, OpenVPN uses UDP port 1194, but this might vary depending on your configuration.

You can check the OpenVPN configuration file to confirm the port:

• Open the OpenVPN server configuration file (usually located at /etc/openvpn/server.conf or similar):

  sudo nano /etc/openvpn/server.conf

• Look for the line that specifies the port and protocol:

  port 1194
  proto udp

In this example, OpenVPN is using UDP port 1194.

2. Configure iptables Rules

You need to add iptables rules to allow traffic on the OpenVPN port.

Add Rules for OpenVPN Port

• Open a terminal and use the following commands to allow traffic on the specified port. Replace 1194 with the port number OpenVPN is using if it differs. For UDP:

  sudo iptables -A INPUT -p udp --dport 1194 -j ACCEPT

For TCP (if OpenVPN is using TCP):

  sudo iptables -A INPUT -p tcp --dport 1194 -j ACCEPT

• Ensure that the rule allows traffic from established connections to continue:

  sudo iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT

Save the iptables Rules

To make sure the changes persist after a reboot, save the iptables rules.

• On CentOS 6.x, use the following command to save the rules:

  sudo service iptables save

3. Restart the iptables Service

To apply the new rules immediately, restart the iptables service:

sudo service iptables restart

4. Verify the Firewall Rules

To confirm that your rules have been applied correctly, you can list the current iptables rules:

sudo iptables -L -n -v

Look for the rules you added to ensure they are in place.

5. Check SELinux Configuration (if applicable)

If SELinux is enabled on your CentOS 6.5 system, it might also be enforcing additional security policies. You might need to adjust SELinux policies to allow OpenVPN traffic.

• Check the SELinux status:

  getenforce

• If SELinux is enforcing, and you encounter issues, you can temporarily set it to permissive mode for testing:

  sudo setenforce 0

• If OpenVPN works with SELinux in permissive mode, you may need to adjust SELinux policies to permanently allow OpenVPN traffic.

By following these steps, you should be able to allow OpenVPN traffic through the specific port on CentOS 6.5. If you run into issues or need further customization, checking OpenVPN and CentOS documentation might be helpful.

Conclusion

To permit OpenVPN traffic with the help of a particular port on CentOS 6.5, then you want to have the firewall to easily permit traffic on the specific port that is used by OpenVPN and have managed odoo server solutions. CentOS 6.5 utilizes iptables for management of firewalls.