Introducing a new Drupal module built by me and my good friend Sumesh. The module's name is checkpost and it's basically a development module like shield but instead of using a username/password, it used header based authentication.
You should be able to add any custom headers and validate against a set value. You should also be able to exclude pages and IP addresses (in CIDR format as well). So if you add the entry 220.127.116.11/20 in the "Ignore source IPs" field in the config form of the module, you'll be allowing access to requests from the IP address range of 18.104.22.168 - 22.214.171.124. You can calculate CIDR address ranges here: https://mxtoolbox.com/subnetcalculator.aspx