all-knowing-dnsp - Online in the Cloud

PROGRAM:

NAME

all-knowing-dns - Tiny DNS server for IPv6 Reverse DNS

SYNOPSIS

all-knowing-dns [--configfile <path>] [--querylog]

DESCRIPTION

AllKnowingDNS provides reverse DNS for IPv6 networks which use SLAAC (autoconf), e.g. for
a /64 network.

The problem with IPv6 reverse DNS and traditional nameservers is that the nameserver
requires you to provide a zone file. Assuming you want to provide RDNS for a /64 network,
you have 2**64 = 18446744073709551616 different usable IP addresses (a little less if you
are using SLAAC). Providing a zone file for that, even in a very terse notation, would
consume a huge amount of disk space and could not possibly be held in the memory of the
computers we have nowadays.

AllKnowingDNS instead generates PTR and AAAA records on the fly. You only configure which
network you want to serve and what your entries should look like.

OPTIONS

--configfile=path
Use path instead of /etc/all-knowing-dns.conf as configuration file.

--querylog
Enable logging every query to stdout (for debugging).

CONFIGURATION FILE (/etc/all-knowing-dns.conf)

The configuration file is wonderfully simple:

# Configuration file for AllKnowingDNS v1.7

listen 79.140.39.197
listen 2001:4d88:100e:1::3

# RaumZeitLabor
network 2001:4d88:100e:ccc0::/64
resolves to ipv6-%DIGITS%.nutzer.raumzeitlabor.de
with upstream 2001:4d88:100e:1::2

# Chaostreff
network 2001:4d88:100e:cd1::/64
resolves to ipv6-%DIGITS%.treff.noname-ev.de

This example contains all configuration directives. Let's go over them one by one:

listen address
Listens on the given address (IPv4 and IPv6 is supported) on port 53.

network network
Specifies that queries for PTR records within the given network should be answered
(any query for an unconfigured network will be answered with NXDOMAIN). You need to
specify at least the resolves to directive afterwards.

resolves to address
Specifies the address to which PTR records should resolve. The address needs to
contain %DIGITS% exactly once. When answering AAAA queries, %DIGITS% will be parsed
and converted back to an IPv6 address.

Example:

network 2001:4d88:100e:ccc0::/64
resolves to ipv6-%DIGITS%.nutzer.raumzeitlabor.de

Example query:

The PTR query 2001:4d88:100e:ccc0:216:eaff:fecb:826 will resolve to
ipv6-0216eafffecb0826.nutzer.raumzeitlabor.de

with upstream address
Before answering a PTR query for this network, AllKnowingDNS will ask the DNS server
at address first, appending .upstream to the query.

Example:

network 2001:4d88:100e:ccc0::/64
resolves to ipv6-%DIGITS%.nutzer.raumzeitlabor.de
with upstream 2001:4d88:100e:1::2

Example query:

The PTR query 2001:4d88:100e:ccc0:219:dbff:fe43:2ec5 will make
AllKnowingDNS ask for
5.c.e.2.3.4.e.f.f.f.b.d.9.1.2.0.0.c.c.c.e.0.0.1.
8.8.d.4.1.0.0.2.ip6.arpa.upstream. at 2001:4d88:100e:1::2
and relay the answer, if any.

DELEGATING ZONES

This section shows you how to delegate a zone in BIND9 or any DNS server with a compatible
zone file syntax. To use AllKnowingDNS, you need to delegate the appropriate .ip6.arpa
zone for your network and one regular domain.

REVERSE DELEGATION (.ip6.arpa)
$ORIGIN .
$TTL 604800 ; 1 week
e.0.0.1.8.8.d.4.1.0.0.2.ip6.arpa IN SOA infra.in.zekjur.net.
hostmaster.zekjur.net. (
20 ; serial
604800 ; refresh (1 week)
86400 ; retry (1 day)
2419200 ; expire (4 weeks)
604800 ; minimum (1 week)
)
NS libri.sur5r.net.
NS infra.in.zekjur.net.

; net for RaumZeitLabor
0.c.c.c.e.0.0.1.8.8.d.4.1.0.0.2.ip6.arpa. IN NS ipv6-rdns.zekjur.net.

FORWARD DELEGATION (.nutzer.raumzeitlabor.de)
$TTL 6h
raumzeitlabor.de IN SOA ns1.jpru.de. hostmaster.jpru.de. (
2012030701
3h
30m
7d
1d )
IN NS ns1.jpru.de.
IN NS ns2.jpru.de.
IN A 195.49.138.121
IN MX 10 rzl.uugrn.org.
IN MX 20 up.uugrn.org.
IN MX 50 mail.uugrn.org.
IN MX 100 rzl.uugrn.org.

nutzer.raumzeitlabor.de. IN NS ipv6-rdns.zekjur.net.

VERSION

Version 1.7

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