Re: [Cbor] I-D Action: draft-ietf-cbor-network-addresses-04.txt

Michael Richardson <> Mon, 26 April 2021 00:47 UTC

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From: Michael Richardson <>
To: Carsten Bormann <>, Ole Troan <>,,
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Date: Sun, 25 Apr 2021 20:47:20 -0400
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Subject: Re: [Cbor] I-D Action: draft-ietf-cbor-network-addresses-04.txt
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Carsten Bormann <> wrote:
    >> - for 261 I would at least include those arguments and make it clear when to use or the other

    > Sounds good to me.

What I'm hearing is that you'd like me to write something like below.

# Introduction

{{RFC8949}} defines a number of CBOR Tags for common items.

Tag 260 and tag 261 was later defined through IANA.
These tags cover addresses (260), and prefixes (261).
Tag 260 distinguishes between IPv4, IPv6 and Ethernet through the length of the byte string only.
Tag 261 was not documented well enough to be used.

The author wanted an explicit indication of IPv4 or IPv6, and the possibility to omit trailing zeroes.

This document provides a format for IPv6 and IPv4 addresses and prefixes.
Prefixes may omit trailing zeroes in the address.
Due to the complexity of testing the value of omitting trailing zeros for addresses was considered non-essential and support for that was removed in this specification.

This document does not deal with 6 or 8-byte ethernet addressees.

Michael Richardson <>   . o O ( IPv6 IøT consulting )
           Sandelman Software Works Inc, Ottawa and Worldwide