DNS servers DO cache data. I believe the default time is 24 hours.
You control the cache time for each domain on your Primary DNS server
in the TTL (TimeToLive) field in the SOA record. What I do is change
the TTL to 5 minutes and wait 24 hours for everyone to get the rapidly
updating record, then I make the change, wait to verify that all is
working well, then change the TTL back to 24 hours. Seems to work well
for me.
One note, the times listed in the SOA record are in seconds. (1 day =
86400 seconds)
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Bill Fisher 619.678.8899 x 773 Bill@excelsoft.com
Manager, Network Operations
ExcelSoft Technology http://www.excelsoft.com
He who throws mud loses ground. -Unknown
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
----------
> From: Paul T Laudenslager <ptl@monumental.com>
> To: ntisp@emerald.iea.com
> Subject: Do DNS Servers cache?
> Date: Tuesday, April 07, 1998 6:44 AM
>
> I've moved a few client websites over to another machine (NT4AS/IIS)
on a
> different subnet. I'm responsible for both the Primary and Secondary
DNS
> servers (NT4DNS) for these domains.
>
> I've updated a few IP's on both the primary and secondary DNS's to
point to
> the new website locations. It works fine from the machines that use
these
> DNSs as their default DNS and I've verified them using nslookup.
>
> My problem is...
> I've tried bring up the 'new' sites from two other locations and it
seems
> they are still pointing to the old IP address. When I went into
nslookup (it
> defaulted to their own DNS servers - not mine), it reported the 'old'
IP
> (non-authoritative).
>
> Do other DNS servers cache IP's from remote domains? If so, how long
can I
> expect before the cache on these services to flush and update
themselves?
>
> Thanks in advance for your time and consideration.
>
> Paul L.
>
>
> ----------------------------------------------------------
> NTISP Mailing List listserver@emerald.iea.com