Never rely exclusively on `httpbin.org/ip` or `ip-api.com` when checking 50,000 proxies—they rate-limit your checker or return cached responses! Deploy this 10-line `azenv.php` script on 3 cheap VPS nodes (US-East, EU-Central, Asia-SG): ```php <?php header('Content-Type: text/plain'); foreach ($_SERVER as $k => $v) { if (strpos($k, 'HTTP_') === 0 || in_array($k, ['REMOTE_ADDR', 'REMOTE_PORT', 'REQUEST_METHOD'])) { echo "$k = $v\n"; } } ``` Zero database overhead, `<1ms` execution time, and instantaneously reveals `HTTP_X_FORWARDED_FOR`, `HTTP_VIA`, and `REMOTE_ADDR` to classify Elite (L1) vs Anonymous (L2) vs Transparent (L3).