How long does DNS name server take to propagate to the Internet?

  • Thread starter Thread starter Chien Lau
  • Start date Start date
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Chien Lau

Hi,

I've got a basic question for you: I was hosting my external DNS using
Windows 2000, but yesterday I moved all of my DNS zones to a 3rd party DNS
provider called UltraDNS. I then logged on to my registrar's website and
pointed the name servers for my domain to:

udns1.ultradns.net
udns2.ultradns.net

I also *deleted* references to the previous nameservers. Some Internet
users are now able to resolve hostnames in my domain, while others are not.
Can you tell me how long it takes for this type of change to propagate out
through the Internet? Are we talking days, weeks, or..?

Thanks,

Sal Bompensaro
 
It depends on when the last updates occured, when you actually made the
changes and whether or not the old record had been seen by someone.
Typically a 24-hour lag is what you should expect for new records. Old
records that have been modified may not be noticed until the original TTL
expires on a client that has previously requested and cached those records.
Some ISP say 72-hours is their norm

--
Sincerely,

Dèjì Akómöláfé, MCSE MCSA MCP+I
Microsoft MVP - Directory Services
www.readymaids.com - we know IT
www.akomolafe.com
Do you now realize that Today is the Tomorrow you were worried about
Yesterday? -anon
 
Deji Akomolafe said:
It depends on when the last updates occured, when you actually made the
changes and whether or not the old record had been seen by someone.
Typically a 24-hour lag is what you should expect for new records. Old
records that have been modified may not be noticed until the original TTL
expires on a client that has previously requested and cached those records.
Some ISP say 72-hours is their norm
Click to expand...

...but the thing is, no records have been changed. They are all the
same. Only the nameservers have changed. Do ISPs cache nameservers as well
as records? In other words, if an AOL customer wants to reach
www.MyDomain.com and the record is not cached, will AOL's DNS server attempt
to contact my **NEW** DNS server at UltraDNS or will it try to contact my
old one instead?

I hope this makes sense...

Thanks, Deji.
 
It's the same. The registrar/ISP publishes the NS records for your Domain.
(Normally) If someone had queried for you domain 1 hour ago, they will cache
the info for your NS for as long as your TTL indicates. If you then change
your NS records at your Registrar, your Registrar will then send the
information to the Registry (being brief here). When the update occurs, the
guy that looked you up 1 hour before you made the changes will not know
about that change until the TTL expires and the information is needed again.
This is the reason why you need to bring down the TTL on your records well
before you make changes.

Just wait it out is all I can say.

--
Sincerely,

Dèjì Akómöláfé, MCSE MCSA MCP+I
Microsoft MVP - Directory Services
www.readymaids.com - we know IT
www.akomolafe.com
Do you now realize that Today is the Tomorrow you were worried about
Yesterday? -anon
 
I have a different take on what you have done . .

If the previous dns servers authoritivative for your domaina are still up
with the correct records, and the new dns servers are holding the same
records, the 12 -24 transition should be seemless to end users. There should
be no interuption of servcie for anyone.

I have change authoritative DNS servers several times with no interuption
during the propagation.
 
I have a different take on what you have done . .
If the previous dns servers authoritivative for your domaina are still up
with the correct records, and the new dns servers are holding the same
records, the 12 -24 transition should be seemless to end users. There should
be no interuption of servcie for anyone.

I have change authoritative DNS servers several times with no interuption
during the propagation.
Click to expand...

Yeah, I came to the same conclusion. By reactivating my old DNS server,
I've ensured that DNS clients will ultimately resolve their queries --
either via my old server or via the new UltraDNS server. I'm just wondering
when I can turn the old DNS server off. I guess all I can do is look at the
firewall logs and when I stop seeing inbound UDP traffic on port 53, I'll
know I can shut off the old server.
 
In
Sal Bompensaro said:
Yeah, I came to the same conclusion. By reactivating
my old DNS server, I've ensured that DNS clients will
ultimately resolve their queries -- either via my old
server or via the new UltraDNS server. I'm just wondering
when I can turn the old DNS server off. I guess all I can
do is look at the firewall logs and when I stop seeing
inbound UDP traffic on port 53, I'll know I can shut off
the old server.
Click to expand...

When the TTL runs out on any cached NS or SOA records on any external DNS
servers. Usually, two days.
 
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