Newtowner is a tool designed to test firewalls and network boundaries by simulating traffic from various global datacenters, helping identify misconfigurations in trust boundaries commonly found in cloud environments. It supports checks for multiple providers like GitHub, GitLab, Bitbucket, AWS, and Cloudflare, and allows users to configure settings for each provider before running tests on specified URLs. The tool focuses on HTTP/HTTPS access differences and does not perform protocol-level checks like port scanning.