Possible conflict between Cloudflare DNS and host DNS

Website, Application, Performance DNS & Network
1

Quick background: Recently, I was installing the cpanel plugin, JetBackup. The installation failed repeatedly during the download phase. I contacted cpanel support, who investigated and determined that they could replicate the error on my server, but not elsewhere. Support personnel tried several steps, including a manual install, and still couldn’t download successfully. Support concluded it was a server issue and not an issue with JetBackup.

Before contacting my hosting provider, I wanted to rule out other possibilities I could fix myself, so I started digging around and noticed some additional DNS entries on the host that are not in Cloudflare’s DNS. My basic question is whether that matters, given the fact that my registrar points the domain to Cloudflare’s nameservers. Does that mean the additional entries in the hosting DNS are irrelevant because only what’s on the authoritative nameserver matters, or does it mean those extra entries could possibly cause interference of some kind? (The frontend of the website operates fine. It’s just the server that may have an issue.

One of the entries is an SOA entry. It’s my understanding that CF generates its own automatically, which takes precedence if the domain is set to use CF nameservers. There are also two entries for the hosting providers nameservers, and three entries that appear to relate to an SSL certificate installed on the host. Except for the SOA entry, the others are all editable and deletable, but I don’t want to mess with that unless I have to. (I’d just ask the hosting company, but based on a nag note I spotted somewhere about having the wrong nameservers, I’m thinking the host is not happy with the NS for the site being CF.)

Does this sound like a possible problem source, or does the answer lie elsewhere?

Thanks in advance for any advice you can offer.

2

Generally yes.

It depends. This configuration is typically known as split brain or split horizon DNS. Anything using Cpanels’s configured DNS resolver as authoritative (services on the local machine generally, sometimes, but not always) aren’t talking to Cloudflare’s DNS servers. That is sometimes a good thing as it allows intraservice communication to happen on the local machine instead of looping through Cloudflare.

3

Ah! It appears I could add Cloudflare’s NS to the Bluehost server configuration in place of the BH ones, but I’m not sure what effect that would have. Since BH seems to disapprove of CF nameservers being used, I already know what answer I’d get from BH support if I asked.

The prudent course would probably be to wait and see if I can resolve the current problem in some other way.

4

I am not a Bliehost customer so i can’t say. I use Dreamhost which is generally functionally equivalent. Dreamhost maintains DNS entries for specific hosts which I copy to my :logo: equivalents because the local servers and services need to know where the origins point but the authoritative DNS of a Cloudflare where it matters.

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Thanks for the advice.

Currently, I’m working with JetBackup support to resolve the problem. Support personnel were able to manually install the plugin and still haven’t figured out what’s causing the issue. Otherwise, the site continues to operate normally.

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