<?php
$ip_cf = $_SERVER['HTTP_CF_CONNECTING_IP'] ?? 'не передан';
$ip_xff = $_SERVER['HTTP_X_FORWARDED_FOR'] ?? 'не передан';
$ip_remote = $_SERVER['REMOTE_ADDR'] ?? 'не передан';

echo "<pre>";
echo "CF-Connecting-IP: $ip_cf\n";
echo "X-Forwarded-For: $ip_xff\n";
echo "REMOTE_ADDR: $ip_remote\n";
echo "</pre>";
?>