COREDNS-SIIT(7)

💫 COREDNS-SIIT(7) — the siit plugin, explained 💫

okay so bestie, pull up a chair 💖 this is the manual page for siit, straight out of the CoreDNS Plugins section, and by the end you're gonna be so comfy with it. no cap.

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✨ NAME ✨

siit — enables AAAA->A translation support for DNS records based on SIIT (IPv6->IPv4 translation). 🦋

literally the whole personality of this plugin in one line.

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🌸 DESCRIPTION 🌸

so here's the vibe: the siit plugin will, when asked for a domain's A record, synthesize it from a corresponding AAAA record — if that AAAA record belongs to a certain IP range. it's giving translator energy 🔥

it also supports arbitrary mapping IPv6->IPv4. yes bestie, arbitrary. we love options 💅

where does this actually eat? it's useful when published services are IPv6-only and emit their AAAA record accordingly, but IPv4 clients reach them through a siit routing. this plugin generates the associated A records for these clients automatically. main character behavior, honestly 👑

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🎀 SYNTAX 🎀

siit {
    ipv6_prefix IPV6PREFIX
    eam IPV4 IPV6
}

• ipv6_prefix — specifies any local IPv6 prefix to use, instead of the well known prefix (64:ff9b::/96). yes, that's the default, write it down 📝
• eam — translates the ipv6 to the corresponding ipv4, it can be set multiple times 🫶

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⭐ EXAMPLES ⭐

here's a whole config living its life, no notes:

. {
    siit {
        ipv6_prefix 64:1337::/96
    }
}

64:1337::/96… the leetspeak prefix… iconic, honestly 😭

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🔥 METRICS 🔥

if monitoring is enabled (via the prometheus plugin) then the following metrics are exported:

• coredns_siit_requests_translated_total{server} — counter of DNS requests translated 📊

the server label is explained in the prometheus plugin documentation. go read that one if you're nosy (affectionate) 🧚

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💀 BUGS 💀

here's the part where we're honest with each other, bestie 🙈

• Prefix matching in eam is not implemented yet.
• DNSSEC support is not implemented yet. The problem is the same as DNS64. See: RFC 6147 Section 3 ⟨https://www.rfc-editor.org/info/rfc6147/#section-3⟩

like, not broken broken — just not there yet. don't go expecting DNSSEC and then act surprised. consider this your vibe check ⚠️

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🌈 SEE ALSO 🌈

• See RFC 6052 ⟨https://www.rfc-editor.org/info/rfc6052/⟩ for more information on the SIIT mechanism
• and RFC 7757 ⟨https://www.rfc-editor.org/info/rfc7757/⟩ about the explicit address mappings (eam) mechanism

reading RFCs is self-care, allegedly 💜

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🍓 NOTES 🍓

This plugin is heavily based on dns64 plugin ⟨../dns64⟩. family tree real 🫶

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and that's the whole page!! mwah 💋 — with love from the CoreDNS crew, October 2026, COREDNS-SIIT(7), manual name and all. now go translate some records, you absolute icon 👑✨