In order to serve content, our servers first need to contact your origin server based on the Origin URL that you've set. If you want to modify your responses, whitelist or firewall our servers there are several methods of doing this.
CDN-ServerId HTTP Header
The most basic method of detecting our edge server is to look for the CDN-ServerId header in your backend. Our servers will always send this header with all the requests and the value will include the internal server ID.
Dedicated Origin URL Hostname
Another way of whitelisting our infrastructure would be to use a hard to guess custom hostname as the OriginURL that only our servers would access. While only secured by obscurity, this method does provide a very convenient way of securing your origin.
Edge Server IP List API
We also provide an API that automatically returns the list of IPs that are currently used by the BunnyCDN network. However, due to the design of our system, these can change relatively frequently, so we highly suggest to automate this to prevent connectivity problems. Please find the IP list here: https://bunnycdn.com/api/system/edgeserverlist and https://bunnycdn.com/api/system/edgeserverlist/IPv6