This is a developer / utility module to help with configuring and debugging Trusted Proxy Headers.
Initially it has a very no-frills UI.
It produces a report which shows what Reverse / Trusted Proxy configuration has been found in settings, along with the Trusted Headers which Drupal passes through to Symfony's Request handling code, and some of the properties of the Request which Symfony/Drupal derived using the current settings.
This might help set up - for example - proper detection of Client IPs for sites running behind proxies.
See: