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FTSC                            FIDONET TECHNICAL STANDARDS COMMITTEE
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Publication:    FSP-1035
Revision:       1
Title:          DNS Distributed Nodelist
Author(s):      Alexey Vissarionov, 2:5020/545
Issue Date:     03 Nov 2008
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Contents:
0. Introduction
1. Translation of a Fidonet address into a host name
2. Flag indicating root internet domain
3. Service port location


0. Introduction

Abstract:

This document describes the method of distributing Fidonet nodelist
data through the DNS infrastructure for use by IP-capable Fidonet
mailers.

Status:

This document is a Fidonet Standards Proposal (FSP) - it specifies
the best current practices for the Fidonet community, and requests
discussion and suggestions for improvements. It is released to the
public domain, and may be used, copied or modified for any purpose
whatever.


1. Translation of a Fidonet address into a host name.

The format of Fidonet address is:

Z:N/F.P@W

Where the fields are:

Z - Zone Number:
        The zone the node is part of.

N - Net Number:
        The network the node is a member of.

F - Node Number:
        The actual node number.

P - Point Number:
        If the system is a point rather than a node then
        this is their point number at that node.
        Optional. If ".P" is missing then assume 0 (node itself).

W - Network name:
        The name of the "Fidonet Technology Network".
        Optional.

Fidonet address should be translated into host name as:

[pP.]fF.nN.zZ.RD.

where the fields refer to...

P       - Point Number, as in Fidonet address (FA)
        If "pP." is missing then assume 0 (node itself).

F       - Node Number, as in FA
        Must be present.

N       - Net Number, as in FA
        Must be present.

Z       - Zone Number, as in FA
        Must be present.

RD      - Root Domain, as specified in nodelist.
        Must be present.

Please note the trailing dot - it should exist in "host name"
parameter when making the DNS query to avoid resolving hosts
like "f545.n5020.z2.fidonet.net.corp.example.com."


2. Flag indicating root internet domain.

To indicate the root internet domain which should be used for
translation of a Fidonet address into internet domain name
there is a need to introduce the special nodelist flag.
This flag is not inherited: if it is specified for a zone, it
affects only the administrative nodes, and if it is specified
for a region, it affects only independent nodes of that region.

The format for this flag is:
 IRD:domain.name

This flag is valid only for Zone, Region and Host entries.

The following is valid example:

Zone,2, ... ,IRD:fidonet.org, ...
; "f0.n2.z2.fidonet.org." is the Z2C's (2:2/0) host address
Region,50, ...
; no IRD means no DNS capability for independent nodes in the region
Host,5020, ... ,IRD:fidonet.net, ...
; "f545.n5020.z2.fidonet.net." is the host address for 2:5020/545


3. Service port location.

If a node accepts connections on a non-standard port, NS zone should
contain SRV record for it.

Format of SRV record is:

_service._proto.name    IN SRV  priority weight port host

Where the fields are:

service:        service name - "binkp" or "ifcico";
                other names may be added in the future
proto:          protocol family - only "tcp" used for now
name:           record name
priority:       host priority, lower value means more preferred;
                if record contains only one host, this value should
                be set to zero
weight:         relative weight for records with the same priority,
                used for load-balancing; if no load-balancing is
                performed, this value should be set to zero
port:           decimal number of the TCP or UDP port
host:           the hostname of the machine providing the service

* If no SRV record exists, then default port must be used.
* If A or CNAME record exists, then it must be used.
* If no A or CNAME record exists for a node, then host name should be
taken from "host" field of SRV record.
* CNAME targets must not be queried for SRV records.

Examples:

; standard port
f1111                   IN CNAME        fido.example.net.

; non-standard port, A record
_binkp._tcp.f2222       IN SRV          0 0 12345 f2222
f2222                   IN A            10.20.30.40

; non-standard port, CNAME record
_binkp._tcp.f3333       IN SRV          0 0 12345 f3333
f3333                   IN CNAME        fido.example.net.

; everything is in the SRV record
_ifcico._tcp.f4444      IN SRV          0 0 54321 fido.example.net.


History
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Rev 1: First release

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