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	Fri, 19 Sep 1997 15:46:11 +0930 (CST)
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Date: Fri, 19 Sep 1997 15:46:11 +0930
From: Greg Lehey <grog@lemis.com>
To: dg@root.com
Cc: "Jamil J. Weatherbee" <jamil@counterintelligence.ml.org>,
        questions@FreeBSD.ORG
Subject: Re: NAMESERVER Setup Problems
References: <19970919130706.11719@lemis.com> <199709190505.WAA26780@implode.root.com>
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In-Reply-To: <199709190505.WAA26780@implode.root.com>; from David Greenman on Thu, Sep 18, 1997 at 10:05:04PM -0700
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On Thu, Sep 18, 1997 at 10:05:04PM -0700, David Greenman wrote:
>> On Thu, Sep 18, 1997 at 08:07:28PM -0700, Jamil J. Weatherbee wrote:
>>>
>>>
>>>> OK, let's take this apart:
>>>>>
>>>>> @        IN        SOA        acroal.com.   root.acroal.com.
>>>>>                               (  1997091200     ; serial
>>>>>                                  10800          ; refresh
>>>>>                                  900            ; retry
>>>>>                                  604800         ; expire
>>>>>                                  43200 )        ; minimum
>>>
>>>
>>> Thats interesting, the SOA for who.cdrom.com uses these same times.
>>
>> So it does.  It doesn't make it right.
>
>    Wrong. Not only is the refresh number not too short, but in fact it should
> probably be even shorter - 3 hours is a rather long time between serial number
> checks. Paul Vixie recently suggested that this should be on the order of 30
> minutes or less.

I disagree compeletely.  This just creates unneccessary network
traffic.  The refresh time should reflect the frequency of your
configuration changes.  Most systems don't change their DNS
configuration significantly more than once a month, and usually it's
planned.

Of course, the *correct* way to do it would be to find a way to inform
systems which have queried the zone in the previous <refresh> seconds.

Greg