DNS propagation - why is a subdomain only accessible minutes after it's creation (own nameservers)

Gulnor

Registered
Jul 10, 2014
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Root Administrator
Hi everybody

we have question about the behavior of DNS propagation for subdomains.

Here's the scenario we are trying to achieve:

User1 registers at our site "company.com". A subdomain "user1.company.com" is automatically created, not as add-on domain of "company.com", but as standalone account in WHM.

So, an own zone is being created & an A record is being set (same IP as company.com)
NS records are also set to "ns1.domain2.com + ns2.domain2.com", our own nameservers
(no clustering, 2 different IP's, BIND method, they are provided for the moment by the same WHM installation as for company.com & subdomains)
Domain2.com is handled by our registrar GoDaddy, nameservers ns1 + ns2 are also defined there.

Our problem is that right after the creation the domain "user1.company.com" is not immediately accessible (unlike an add-on domain).

When we nslookup for example the new domain "user1.company.com" with the nameservers from our ISP, right after it's creation, we get "Non-existent domain". Then, after 1-15 minutes, and depending on the DNS we try, the nslookup answers with the correct IP address. The DNS from Google (8.8.8.8) for example immediately! answers with the correct IP address.

What exactly happens when the user tries to access his subdomain "user1.company.com"? Are our nameservers contacted to resolve the subdomain or are the subdomains somehow propagated across the DNS servers worldwide? But why does Google's DNS answer immediately, propagation can't be so fast!

Any ideas where may be the problem and how to make a subdomain account accessible immediately after its creation, regardless of the DNS being used by the user?

Many thanks

Marc
 

vanessa

Well-Known Member
PartnerNOC
Sep 26, 2006
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Virginia Beach, VA
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DataCenter Provider
Re: DNS propagation - why is a subdomain only accessible minutes after it's creation (own nameserver

Whether the subdomain is immediately available depends on the user's own local resolvers, which are usually provided by their ISP. You don't really have control over propagation time, but generally speaking, if a user has not accessed the subdomain before, it should load somewhat immediately on the first attempt if it is indeed configured in your nameservers. Not all resolvers work this way though.
 

cPanelMichael

Administrator
Staff member
Apr 11, 2011
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Re: DNS propagation - why is a subdomain only accessible minutes after it's creation (own nameserver

Hello :)

Yes, as Vanessa mentioned, this depends on the resolvers used by a user's local machine. The fact that Google's resolvers output the correct data right away indicates the DNS itself is configured correctly.

Thank you.