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RE: DNS Updates

  • From: Karyn Ulriksen
  • Date: Wed Sep 20 19:20:53 2000

Ben,
 
   There is no major list for when DNS servers update.  Basically, it works like this....
 
    Part of your DNS records has information on how long to store information on a DNS server once it is gathered.  The remote DNS server (ie, Earthlink's) takes the information as a "recommendation".  Most DNS servers will go by this recommendation.  However, there are quite a few DNS servers out there that will ignore the recommendation.  Generally, the servers that disregard the recommended time will update with new information only after a time configured by their administrator.  In most cases, this will be about 24-48 hours.  However, some ISPs may lengthen these times for whatever reason or possibly due to misconfiguration.
 
    If you are not seeing updates as quickly as you'd like, have your ISP set the information in the SOA portion of your DNS record to be short lived.  If the current information is set to 30 days, some DNS servers may not see your new information until after 30 days and there may be little you can do about the current state.  Ask your current DNS provider to set your TTLs for your domain to 24-48 hours to alleviate this type of problem in the future.  If they don't know how to do this, you may want to arrange for a new DNS provider.

---------------------------------------------------------------------
Best regards,

Karyn Ulriksen
Director of Network Operations
PublicHost, A SiteStream Company
22 Mauchly, Suite 200
Irvine, California  92618  USA
Phone: (949) 743-2000
email: kulriksen@publichost.com
URL:  http://www.publichost.com
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-----Original Message-----
From: Benjamin Harper [mailto:harperb@hotmail.com]
Sent: Wednesday, September 20, 2000 3:06 PM
To: nanog@merit.edu
Subject: DNS Updates

Hi Everyone,
I was wondering if anybody knew when most DNS servers update their records with regard to changes in DNS hosts for a domain.  I've made changes to my domain, and it looks like only a handful of DNS servers (earthlink being one of them that I could find) have actually made the changes.  I've heard that the turnaround time is normally 24-48 hours for the changes to take effect, yet it seems that it takes FOREVER for anything to ever happen when I have NSI update the records for the site.  Is there a reference on the net somewhere containing when some of the major DNS servers update their records, or does anybody have any idea why it always takes so long? 
 
Many Thanks,
Ben