Sub-domains on CloudFlare are marked with an orange cloud. Sub-domains not on CloudFlare are marked with a grey cloud.
The CloudFlare network can only proxy web traffic over port 80 and 443. The following sub-domains should be marked with a grey cloud to prevent performance issues:
- cpanel
- direct
- ftp
- ghs.google.com
- mail and webmail
- SSH
- mysql
- nameservers (NS1, NS2)
- secure* (unless you enable CloudFlare SSL)