CDN site is not caching
To confirm your CDN site is not caching, use curl -I command. You should always get MISS as result. Refer to http://cdn77.com/support/knowledgebase/cdn-resource/how-to-check-if-a-file-is-cached-or-not-cached
When your CDN URL is not caching, it can be caused by the following:
1) Origin Cache-Control header set as no-cache or value: 0
2) Cookies are enabled, you have to enable "Ignore Set Cookies" in your CDN Resource settings under the tab "Other Settings".
3) Expiry header comes before Cache-Control header. Our system will honor the order of web header. If expiry header is set to an old date, then the content will never be cached.
4) You get a 301/302 redirection when you are performing a curl -I on your CDN URL. You may need to remove the redirection from your origin server, or use IP of your Origin (if the redirection rule do not apply on IP).
Anyway, feel free to contact our support team if you are still getting bad results.