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

Michael Richardson <mcr+ietf@sandelman.ca> Mon, 26 April 2021 00:06 UTC

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From: Michael Richardson <mcr+ietf@sandelman.ca>
To: Ole Troan <otroan@employees.org>
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Subject: Re: [Cbor] I-D Action: draft-ietf-cbor-network-addresses-04.txt
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Ole Troan <otroan@employees.org> wrote:
    > - for 261 I would at least include those arguments and make it clear
    > when to use or the other

I'm not sure it's fair to criticise 261.

    > - so you don’t want to support the commonly used shortcut of specifying
    > both and address and a prefix in one?

I don't understand your suggestion.
    X - address
[n,X] - prefix

    > - in ip agnostic code I often find I just need an IP address instead of
    > having to care if it’s 4 or 6. It would therefore be nice with a
    > general IP address and ip prefix type too.

So, I think that I've done this.

When you find that you need a v4 or a v6 in your schema, you would just write
"IPaddress", and then let the tag tell your decoder whether it was v4 or v6.

I used this CDDL in my use case:

IPaddress = #6.260(v6addr) / #6.261(v4addr)
IPsubnet  = #6.260([prefixlen, v6addr])
          / #6.261([prefixlen, v4addr])
prefixlen = uint
v6addr    = bytes .size 16
v4addr    = bytes .size 4

--
Michael Richardson <mcr+IETF@sandelman.ca>   . o O ( IPv6 IøT consulting )
           Sandelman Software Works Inc, Ottawa and Worldwide