Split Horizon DNS issue

dns

#1

Hello,

We have a website on a domain that we are having issues with. Here’s what we are experiencing:

On internal office network:

  • Certain images do not display on the webpage
  • Website does not automatically redirect form http to https

On external network (away from office):

  • Website displays fine
  • http to https redirection works fine.

We have a Split DNS setup here in the office. We have a local DNS server that we manage for DNS. We’ve mirrored the DNS setting that we have configured in CloudFare for this domain on our local DNS server, but are still having issues.


#2

I’d recommend pointing your internal DNS to the Cloudflare proxy address of the site, not the origin server itself. If you are pointing directly to the origin, Cloudflare isn’t involved and thus things like SSL aren’t handled by us.


#3

Hello,

Thanks for the suggestion. Where do I find the Cloudflare proxy address?


#4

Thanks! Our website is good now.


#5

Another thing to note here is that its never a good idea to “hard code” Cloudflare IPs (e.g. A/AAAA). Instead, after activation (and even when using Cloudflare DNS authoritatively) you can point to a CNAME record available from Cloudflare. For example, if I have example.com on Cloudflare with a www subdomain defined, I can point to www.example.com.cdn.cloudflare.net. This is where split horizon/brain domains should point to use Cloudflare.

Note that this is available on any plan/setup BUT if you haven’t activated then your zone will eventually be automatically removed from Cloudflare. All domains on Cloudflare must activate or they may be removed (to make way for others).