Nameserver Propigation

[tfelice]

I just moved a domain to a new hosting company. I made the neccessary changes with the domain registrar a couple of days ago. Earlier today, the domain was pointing to the new IP address, but now it has gone back to the old address. Is this common or is there a potential problem?

[Hunter]

Normal, it can take up to 72 hours to propagate fully. In the meantime it can fluctuate back and forth.

[tfelice]

Thanks. I thought so, but wanted to check. It has probably been 3 years since I have had to move a site from one host to another.

[Zaphod Beeblebrox]

In my experience it usually takes less than a day.

[ronburk]

Whenever a program (such as a web browser) queries a name server to translate a domain name into an IP address, the name server response includes a field that specifies how long that response is valid. This is often set to be a few hours, but can be set to a wide range of values. Thus, the amount of time required for your name change to propagate through the Internet (expire, really) greatly depends on how the authoritative name server(s) for your domain set that field.

Of course, name translation information is cached in a great many places throughout the Internet, and not all such software obeys the expiration protocol correctly, further randomizing the time required for a change to propagate "everywhere".

If you know you are going to move domains, and you run your own name server or have a friendly ISP, you could have the expiration time cranked down to a very short period the day before you're making the move.