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I just did an overhaul of my company's website and changed the hosting provider, and it's probably been about 36-48 hours since I changed the pointers at my registrar to the new name servers. I have noticed some very strange behavior at my office, where we have a Windows Server domain-based LAN-- in particular, with two computers sitting next to one another, one pulls up the new site and the other does not--after repeatedly clearing the cache, resetting/flushing via ipconfig, trying different browsers, etc.--which is baffling to me. I was testing the site on someone's phone, and pulling up the site via the in-house wi-fi connection brought up the old version, while switching to his phone's LTE data connection pulled up the new one.

What exactly is going on here? Clearly those computers pulling up the old version of the site are referencing the old DNS pointers that link to the old hosting provider, but how could this vary from machine to machine on the same network?

Thanks for any clarification here.

  • For future migrations, you should first use have the same A records in the old and new name server. In the new servers the TTL for A records should be something like 5 minutes or so. Then, make the DNS server change for the domain, and after you have confirmed the DNS server has been changed, proceed to change the A records to point to the new site. This way you will get the fastest switchover to the new site. – Tero Kilkanen May 1 '14 at 11:48
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If you were using Chrome browser, then you should know that Chrome uses Google's DNS.

Also, switching to LTE data connection on your phone you switch to another DNS supplied by your carrier. If you have Google Bandwidth saving feature enabled, that would also make you use Google Proxy server's and probably their DNS (to an extent).

You also mention clearing the cache, but it's not very clear where did you clear it. There might be cache on your routers, then there is also DNS cache on clients (browser and/or OS-level).

It all comes down to one thing: DNS servers update at different times and this is a normal thing.

  • ok, thanks for the response. That's particularly interesting about Chrome using Google's DNS-- I figured, when all is said and done, it's entirely reliant upon the ISP/data source, but clearly there are other factors at work. In clearing the cache, it was on a browser level as well as using ipconfig to reset & clear the adapter settings. – nickpish May 1 '14 at 8:27

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