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Re: [DNSOP] [Ext] I-D Action: draft-ietf-dnsop-serve-stale-03.txt

Tony Finch <dot@dotat.at> Tue, 05 March 2019 18:13 UTC

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Date: Tue, 05 Mar 2019 18:13:38 +0000
From: Tony Finch <dot@dotat.at>
To: Paul Wouters <paul@nohats.ca>
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Subject: Re: [DNSOP] [Ext] I-D Action: draft-ietf-dnsop-serve-stale-03.txt
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Tony Finch <dot@dotat.at> wrote:
>
> Say you have a partially-lame zone, where some servers might have an
> expired copy (returning SERVFAIL) and some might not know about the zone
> at all (returning REFUSED or referrals to the root). Typically (without
> serve-stale) a resolver will react by adding a lame server cache entry and
> re-trying other hopefully working servers.
>
> I think serve-stale should only take effect after this point, if a zone
> has at least one non-lame server, and all the non-lame servers do not
> respond.

D'oh, sorry, I missed out the important case:

If the zone has a mixture of lame and working servers, the lame servers
should not trigger serve-stale, because the resolver still needs to try
asking the working servers.

Tony.
-- 
f.anthony.n.finch  <dot@dotat.at>  http://dotat.at/
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