Accessing subdomain before and after DNS update

Hello, I have this scenario (for a blog system):

To check it’s availability, a user accesses a subdomain that doesn’t exist so Chrome says DNS_PROBE_FINISHED_NXDOMAIN no IP found.

After that, he creates an account with that subdomain, so the system updates the DNS to add it and the subdomain is accessible, HOWEVER :

  • for new users accessing that subdomain, it works directly
  • for the initial user, even if he refreshes Chrome, it still says DNS_PROBE_FINISHED_NXDOMAIN!

Actually, even if he accesses it from his phone it still says DNS_PROBE_FINISHED_NXDOMAIN, but if he goes on the phone on the 4G network, it works so it’s not Chrome’s fault but his wifi network keeping its cache.

The question: how can this be overcome so that the subdomain can work for him after it was created without him needing to go to other wifi/4G.

I am using Cloudflare for the DNS so it doesn’t allow wildcard subdomains soI have to create them through a script, however if the domain was accessed before it was created on Cloudflare, it still won’t be accessible on the same network until cache is updated which can take a day?

That’s DNS caching (TTL). You’ll have to wait for that bad request to clear from cache. I think it depends on default TTL for that domain.

Why not have the user try some other method, like checking for an “A” record at

Thank you I actually have the client check my database but if he checks directly in his browser it creates that situation

There’s nothing you can do about that. They’re unknowingly shooting themselves in the foot. The best you can do is post a dramatic warning to not do this.

This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.