Custom "firewall-start" scripts, such as those found on GitHub Gists , allow for advanced IP blacklisting and traffic monitoring that exceeds factory settings.

While these "codes" offer great power, they also carry risks. Executing unknown scripts can leave a router vulnerable to remote code execution (RCE) if the code is malicious. Download Center | Official Support | ASUS Global

The primary use of these .txt or .sh files is to modify the router’s behavior through the Command Line Interface (CLI) or the JFFS (Journaling Flash File System) partition .