dns64

dns64 enables DNS64 IPv6 transition mechanism.

Description

The dns64 plugin will when asked for a domain’s AAAA records, but only finds A records, synthesizes the AAAA records from the A records.

The synthesis is only performed if the query came in via IPv6.

This translation is for IPv6-only networks that have NAT64.

Syntax

dns64 [PREFIX]
  • PREFIX defines a custom prefix instead of the default 64:ff9b::/96.

Or use this slightly longer form with more options:

dns64 [PREFIX] {
    [translate_all]
    prefix PREFIX
}
  • prefix specifies any local IPv6 prefix to use, instead of the well known prefix (64:ff9b::/96)
  • translate_all translates all queries, including responses that have AAAA results.

Examples

Translate with the default well known prefix. Applies to all queries (if they came in over IPv6).

. {
    dns64
}

Use a custom prefix.

. {
    dns64 64:1337::/96
}

Or

. {
    dns64 {
        prefix 64:1337::/96
    }
}

Enable translation even if an existing AAAA record is present.

. {
    dns64 {
        translate_all
    }
}

Metrics

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

  • coredns_dns64_requests_translated_total{server} - counter of DNS requests translated

The server label is explained in the prometheus plugin documentation.

Bugs

Not all features required by DNS64 are implemented, only basic AAAA synthesis.

  • Support “mapping of separate IPv4 ranges to separate IPv6 prefixes”
  • Resolve PTR records
  • Make resolver DNSSEC aware. See: RFC 6147 Section 3

Also See

See RFC 6147 for more information on the DNS64 mechanism.