This is important, before publishing the blog within Blogger, or telling our readers about our new non-BlogSpot blog. Daily, we see anxious queries
I just used the "Buy a Domain For My Blog" wizard, and paid for my domain with my credit card. The credit card company confirmed the charge. But I see that it's "In Transition"??or
You told me how to fix my DNS problem, and I did just what you told me. But I don't see my changes when I Dig the addresses for my domain. I know that I made the changes!
What is going on here? Why do I have to wait, unpredictably?
The answer is reasonably simple - though the symptoms can be intriguingly complex.
- A new domain isn't going to be visible everywhere, immediately, because there are millions of DNS servers, all over the Internet.
Your domain uses one identified DNS server, possibly provided by the registrar, which becomes the authoritative server for your domain. You, and your readers, have your own DNS servers, which you use to retrieve address information for every web site that you access.
When you, or your reader, accesses your domain, your local DNS server provides you the address of your domain, and becomes non-authoritative for your domain.
Each non-authoritative (local) DNS server (that you or your readers - or Google - access) isn't going to immediately retrieve the DNS information for your new domain.
Each DNS server maintains its own master list of all domains on the Internet, and it caches the list on its own terms. Some servers only update their master list once a day, others every 2 or 3 days.
- Changes to an existing domain won't be visible, immediately, because the domain addresses retrieved by each non-authoritative server will be cached on that server.
The cache retention period is based upon Time To Live, which is provided by the authoritative server for the domain. Until the cache expires, the non-authoritative server will continue to provide the addresses previously retrieved.
- Most ISPs and registrars use clusters of servers, geographically separated - and interconnected with multiple communication lines. This strategy protects against any local disaster interrupting service to all customers, simultaneously.
If a DNS server is part of a cluster, there is no guarantee that all servers will update at exactly the same time.
Only one server is authoritative for your domain, at any time. If you (your readers, Google) access the same domain repeatedly, you may get different information each time, until all servers are synchronised with the authoritative server.
If you purchased the domain using "Buy a domain", none of the above became a problem, because of the Transition time period, applied by Blogger. If you setup the domain yourself, after purchasing from a registrar - as is the case for every domain purchased after 2012 - you need to maintain a Transition period, yourself, or expect problems, during the first week or so.
For more discussion, you can read (again, alphabetised):
- Ezine: DNS Propagation Explained - or Why You Have to Wait the 72 Hours
- InterMedia: What is DNS propagation?
- WebHosting: What is DNS propagation and why does it take so long?
- WikiPedia: Domain Name System
And, try this interesting DNS Propagation Checker, for experimentation.