How To Allow VPN Reconnection with UFW Firewall

In this article, we will discuss how to allow VPN reconnection with UFW (Uncomplicated Firewall) without having to disable it. UFW is a user-friendly front-end for managing iptables firewall rules. Its main goal is to make managing iptables easier or, as the name states, uncomplicated.

Monitoring UFW Logs

The first step involves monitoring the UFW logs to identify the IP addresses that are being blocked. This can be achieved by running the following command in the terminal:

sudo tail -f /var/log/ufw.log

The tail command is used to output the last part of files. The -f option tells tail to not stop when the end of the file is reached, but rather to wait for additional data to be appended to the input. The /var/log/ufw.log is the log file for the UFW firewall.

Connecting to VPN

Next, attempt to connect to your VPN using your preferred method, such as gnome-network manager.

Identifying Blocked Connections

In the terminal where you are monitoring the UFW logs, look for lines that contain “[UFW BLOCK]”. These lines indicate outgoing connections that are being blocked by UFW. Note down the IP addresses mentioned in these lines as you will need to allow them in your firewall configuration.

Allowing Blocked IP Addresses

To allow the blocked IP addresses through your firewall, you will need to add rules to your UFW configuration. This can be done using the following commands:

sudo ufw allow out from <IP_ADDRESS_1>
sudo ufw allow out from <IP_ADDRESS_2>

Replace <IP_ADDRESS_1> and <IP_ADDRESS_2> with the IP addresses you noted down earlier. The allow out from command tells UFW to allow outgoing connections from the specified IP address.

Allowing Outgoing Traffic on VPN Interface

In addition to allowing the specific IP addresses, you also need to allow outgoing traffic on the VPN interface (usually tun0). This can be done with the following command:

sudo ufw allow out on tun0

Allowing Specific Ports

If your VPN connection requires specific ports to be open, you can allow them using the following command:

sudo ufw allow out on wlan0 to any port 1194

This command tells UFW to allow outgoing connections on wlan0 (your wireless network interface) to any IP address on port 1194 (the default port for OpenVPN connections). Replace wlan0 and 1194 with your network interface and required port, respectively.

Allowing Necessary Incoming Traffic

Depending on the VPN protocol you are using, you may need to allow certain incoming traffic. Refer to your VPN provider’s documentation for the required ports and protocols.

Verifying UFW Rules

After adding all necessary rules, you can verify your UFW configuration by running the following command:

sudo ufw status verbose

This command will display a detailed output of your current UFW rules.

Conclusion

With these rules in place, you should be able to reconnect to your VPN without disabling UFW. Remember to adjust the IP addresses, ports, and network interfaces according to your specific setup. Regularly review and update your firewall rules to ensure the security of your network.

Remember, managing a firewall is a balance between security and functionality. It’s crucial to only open the necessary ports and IP addresses to maintain a secure network environment.