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PMTA knowledge base›Configuration block§ 3.3.16

<dns>

How the node resolves names
A block about the cache, not about resolvers

The block contains only precache settings: which domains to keep resolved at all times and how often to refresh them. It has three directives.

precached-domains-file names the file with the list of domains — one domain per line. precached-max-domains sets the ceiling on the number of domains taken from that file. precached-refresh-interval — how often to refresh.

Resolvers are not set here. The name-server line lives at the root of the configuration file, as does edns-udp-length. The block’s name suggests that all name resolution settings are gathered in it — that is not so.

The mechanism itself is described in precached-domains.

Example configuration
# the block is only about the cache; resolvers are set outside it
name-server 10.1.2.3
edns-udp-length 1232

<dns>
    precached-domains-file /etc/pmta/precached-domains.txt
    precached-max-domains 500
    precached-refresh-interval 5m
</dns>
yellow — — directive names, blue — blocks. They are highlighted the same way in the text of the card.
Block directives: 3
DNS 3
precached-domains-fileA file listing domains whose DNS is kept fresh at all timesprecached-refresh-intervalHow often precached records are refreshedprecached-max-domainsThe maximum number of domains to keep in the precache
Compatibility
PowerMTA 6.0
described in the manual of this version · platform: any
The vendor does not state the first version for every directive — there is no note here. The name also appears in the 5.0 edition of the manual.
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Related entries

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Referenced from

name-serverGlobalThe precache lives in a separate block but uses the same resolvers. inference

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