1、
the ping www.xx.com if there is CDN, you can try again to remove www
Top-level domain may raise CDN, second-level domain is not necessarily a CDN
Looking from the secondary domain name, provided that the requirements, two (multi-level) domain name with top-level domains on the same server
2、nslookup
3, need FQ site_report? Url = want to check domain name
4, E-mail
