Issue Domain is not resolvable

[Craig1986]

I have recently added a domain, whom Cloudflare are the Registrar, to my Plesk Obsidian Dashboard. Unfortunately, I am having problems with the DNS setup. At present, I am seeing the following 'Domain is not resolvable' message:



This tells me that the issue lies within the DNS. I initially thought that the issue was with the Nameservers. As such, I made sure that the default Nameservers, within Plesk, were accurately changed to the Nameservers within Cloudflare. I then used the MXToolbox resource, which confirmed that propagation had completed.

Unfortunately, the 'Domain is not resolvable' still appears; though the Plesk default page does appear when I visit the domain. Also, I am unable to send and receive emails to/from 3rd party email providers, such as Hotmail and Gmail, though I am able to send and receive emails between the emails associated with this domain.

I have also tried referring to this video but I am still experiencing the same issues.

Any ideas on what could be causing this issue? Am I right in saying that the Nameservers should match the Nameservers within Cloudflare? Either way, both entries cause the same issue.

 

[ddmitrienko]

Hello,

The DNS misconfigurations are quite hard to investigate remotely due to many possible options which also can depend on the desired goals. Most probably, the mail delivery issue, in that case, is also related to the DNS (MX record) misconfiguration (the mail delivery between domains hosted on one Plesk server doesn't involve DNS, that's why you still can "receive emails between the emails associated with this domain").

I would recommend you contacting Plesk support to check and fix this issue directly on the server, with all the details on hand: How to get support directly from Plesk?
P.S. If you decide to do so, please also specify in the support request if you would like to manage DNS on Cloudflare side or through Plesk UI.

 

[Craig1986]

Hello,

The DNS misconfigurations are quite hard to investigate remotely due to many possible options which also can depend on the desired goals. Most probably, the mail delivery issue, in that case, is also related to the DNS (MX record) misconfiguration (the mail delivery between domains hosted on one Plesk server doesn't involve DNS, that's why you still can "receive emails between the emails associated with this domain").

I would recommend you contacting Plesk support to check and fix this issue directly on the server, with all the details on hand: How to get support directly from Plesk?
P.S. If you decide to do so, please also specify in the support request if you would like to manage DNS on Cloudflare side or through Plesk UI.

Thanks for your response.

I have removed the Domain and then re added it, just in case there was some error with the initial setup. I am still getting the following message:

"Domain example.com resolve problems detected:
The domain resolves to the incorrect IP address (xxx.xx.xxx.xxx). To put your website online, correct DNS Settings."

The 'incorrect IP address', which is highlighted above, is not the IP on my VPS. The DNS records, within Plesk, do specify the correct IP address. I have also added the necessary records within Cloudflare. I think it is something to do with the Nameservers.

My setup is that Cloudflare is the domain Registrar and I would like to manage the DNS within Cloudflare. Will I need to change the Nameservers, within the Plesk DNS, to the Nameservers within Cloudflare? I have confused myself on this part, as no matter which one I use, the error still exists after 48 hours but obviously want to ensure I am setting the correct Nameservers, as I try an eliminate all possible errors.

I have since started to get the following message, when sending emails:

"When I Your message couldn't be delivered. The Domain Name System (DNS) reported that the recipient's domain does not exist."

Does this provide any clues as to the potential error?

ps ... I have used the MX Toolbox and it recognises the correct Nameservers as well as the correct IP address.

 

[Craig1986]

It appears there is an issue with the Cloudflare Proxy settings. I am able to send and receive emails, once I set the DNS to 'DNS Only', within the Cloudflare Dashboard.

Is this generally ok or should I still set the MX Record to 'Proxy', on the Cloudflare Dashboard, and look for another solution? I have asked Cloudflare for guidance but they refer me to the Community Support, where I cannot seem to find a clear answer.

 

[ddmitrienko]

I am not sure about the CloudFlare dashboard settings as I'm more about Plesk. For particular CloudFlare configurations, indeed, you need some assistance from someone who knows CloudFlare well.

However, from your goals I can say the following:

1) If you keep DNS management on CloudFlare side (the NS records point to CloudFlare nameservers) DNS settings in Plesk do not have any effect, Plesk just isn't involved in the DNS processes for such domain. DNS in Plesk works only when the domain's NS records point to Plesk IP address as a nameserver (it's configured on CloudFlare side first anyway).

2) From here What is the difference between "Proxied" and "DNS Only"? I see that "DNS Only" is kind of a plain DNS management:

The DNS proxied means it will be shown a Cloudflare IP if you look it up. Thus all attacks at that domain will DDoS Cloudflare and not you host directly.
Non proxied means all traffic goes directly to your own IP without Cloudflare being a safety net in front.
The upside of proxied is that you will enjoy the Coudflare benefits but you can not make a direct connection to your IP, which means any custom ports wont work.
Non proxied has the advantage of being able to use custom ports to connect as it will connect to your IP directly.

You need NS records to point to the CloudFlare nameservers, A and MX records point to (...some A mail.domain_name.com record which poit to..) the Plesk server IP/website IP. MX Toolbox is the right tool to check it in case of "DNS Only". In "Proxy" mode MX Toolbox will show you the CloudFlare's IPs instead.

3) All these settings has to be configured on CloudFlare side, not in Plesk considering the "1)" point. If you see, that in CloudFlare dashboard it has "proper records", but NS, A, MX records are not OK with MX Toolbox in "DNS Only" mode the CloudFlare is the place to look for issue (just like in case with the "Proxy" that you mentioned).

However, the Proxy mode looks like a good benefit from CloudFlare. So, I would configure everything to work in "DNS Only" mode, and after it's OK I would try to make it work with the Proxy mode.