diff --git a/e107_handlers/e107_class.php b/e107_handlers/e107_class.php
index 46a714209..dd92fccec 100644
--- a/e107_handlers/e107_class.php
+++ b/e107_handlers/e107_class.php
@@ -5534,27 +5534,69 @@ class e107
 	 */
 	public function set_urls_deferred()
 	{
-		if(self::isCli())
-		{
-			define('SITEURL', self::getPref('siteurl'));
-			define('SITEURLBASE', rtrim(SITEURL,'/'));
-		}
-		else
-		{
-			define('SITEURLBASE', $this->HTTP_SCHEME.'://'. filter_var($_SERVER['HTTP_HOST'], FILTER_SANITIZE_URL));
-			define('SITEURL', SITEURLBASE.e_HTTP);
-		}
+		$fallback =  $this->HTTP_SCHEME . '://' . filter_var($_SERVER['HTTP_HOST'], FILTER_SANITIZE_URL). e_HTTP; // worst case secenario.
+		$configured_url = self::getPref('siteurl', $fallback);
 
+	    if (self::isCli())
+	    {
+	        define('SITEURL', $configured_url);
+	        define('SITEURLBASE', rtrim(SITEURL, '/'));
+	    }
+	    else
+	    {
 
-		// login/signup
-		define('e_SIGNUP', SITEURL.(file_exists(e_BASE.'customsignup.php') ? 'customsignup.php' : 'signup.php'));
+		    $configured_domain = parse_url($configured_url, PHP_URL_HOST);
 
-		if(!defined('e_LOGIN'))
-		{
-			define('e_LOGIN', SITEURL.(file_exists(e_BASE.'customlogin.php') ? 'customlogin.php' : 'login.php'));
-		}
+		    // Define cache file path in system folder
+		    $cache_file = e_SYSTEM . 'cache/ip_cache.json';
+		    $cache = [];
 
-		return $this;
+		    // Load existing cache if available
+		    if (file_exists($cache_file))
+		    {
+		        $cache = json_decode(file_get_contents($cache_file), true) ?: [];
+		    }
+
+		    // Resolve configured domain IP if not cached
+		    if (!isset($cache[$configured_domain]))
+		    {
+		        $cache[$configured_domain] = gethostbyname($configured_domain);
+		        file_put_contents($cache_file, json_encode($cache, JSON_PRETTY_PRINT));
+		    }
+
+		    $configured_ip = $cache[$configured_domain];
+
+	        $requested_host = filter_var($_SERVER['HTTP_HOST'], FILTER_SANITIZE_URL);
+
+	        // Resolve requested host IP if not cached
+	        if (!isset($cache[$requested_host]))
+	        {
+	            $cache[$requested_host] = gethostbyname($requested_host);
+	            file_put_contents($cache_file, json_encode($cache, JSON_PRETTY_PRINT));
+	        }
+	        $requested_ip = $cache[$requested_host];
+
+	        $allowed_ips = [$configured_ip];
+	        if (in_array($requested_ip, $allowed_ips) && $requested_ip !== $requested_host)
+	        {
+	            define('SITEURLBASE', $this->HTTP_SCHEME . '://' . $requested_host);
+	            define('SITEURL', SITEURLBASE . e_HTTP);
+	        }
+	        else
+	        {
+	            define('SITEURL', $configured_url);
+	            define('SITEURLBASE', rtrim(SITEURL, '/'));
+	        }
+	    }
+
+	    define('e_SIGNUP', SITEURL . (file_exists(e_BASE . 'customsignup.php') ? 'customsignup.php' : 'signup.php'));
+
+	    if (!defined('e_LOGIN'))
+	    {
+	        define('e_LOGIN', SITEURL . (file_exists(e_BASE . 'customlogin.php') ? 'customlogin.php' : 'login.php'));
+	    }
+
+	    return $this;
 	}
 
 	/**