CloudFlare acts as a proxy between your visitors and your servers (our servers if you have been already using our CDN). CloudFlare adds cookies and custom expiry headers to your requests as in the example below.
curl -I mycompany.com
HTTP/1.1 200 OK
Date: Mon, 12 Mar 2013 12:29:32 GMT
Content-Type: text/html; charset=utf-8
Set-Cookie: __cfduid=d27bf7e957ca563b63f4619d8aba12c301395059372558; expires=Mon, 23-Dec-2019 23:50:00 GMT; path=/; domain=.mycompany.com; HttpOnly
These cookies can negatively influence on your CDN cache hit ratio.
The solution is simple. You need to enable Ignore Set-Cookie option in your G-Core CDN control panel. Please refer to Set-Cookie settings for more details.
Differences between CloudFlare and Content Delivery Network (CDN)
CloudFlare acts as a proxy (forward proxy, client proxy) on behalf of the client.
( Client ↔ CloudFlare ) ↔ Server
Content Delivery Network (CDN)
Content Delivery Network (CDN) acts as a reverse proxy (server proxy) on behalf of the server.
Client ↔ ( CDN ↔ Server )
We highly recommend you to check the HTML code of your web page to ensure that URLs have been rewritten properly from your original ones to CNAME from the control panel.
To do that press F12 or open Developers Tools in your browser, choose the Network tab and refresh the page. All static files should have your CNAME in URLs.