Configure the Firewall on Linux

To make sure that the firewall isn’t blocking Barcode to PC, follow these steps:

1) Install UFW if you don't have it:

UFW, or Uncomplicated Firewall, is an interface to iptables that is geared towards simplifying the process of configuring a firewall

2) Enable UFW:

Type sudo ufw enable in your terminal

3) Add the rules:

Type the following commands in your terminal:

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If you want to learn more about UFW

Checkout How To Set Up a Firewall with UFW on Ubuntu 16.04 tutorial by DigitalOcean

Alternatively if you prefer to use iptables

Use these iptables commands:

then, to make the changes permanent:

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