Error 1000 with CloudFlare DNS

Using CloudFlare for DNS and other CDNs can cause CloudFlare to show an Error 1000 indicating that your DNS points to prohibited IP addresses. This occurs when the CNAME records point to Fastly and an origin server is configured as a fully qualified domain name (FQDN) within Fastly:

To solve this error, direct Fastly to use the IP address as the Host for any backend origin servers. This removes the need to resolve the hostname for traffic to the servers:

You can also change this by modifying the VCL configuration files directly. For example, this VCL:

1backend F_Hosting_server_Example_Backend {
2  ...
3  .port = "80";
4  .host = "exampleserver.exampledomain.tld";
5}

would become:

1backend F_Hosting_server_Example_Backend {
2  ...
3  .port = "80";
4  .host = "12.34.56.78";
5}