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

Ole Troan <otroan@employees.org> Sun, 25 April 2021 11:06 UTC

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From: Ole Troan <otroan@employees.org>
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Date: Sun, 25 Apr 2021 13:06:10 +0200
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To: Michael Richardson <mcr+ietf@sandelman.ca>
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Subject: Re: [Cbor] I-D Action: draft-ietf-cbor-network-addresses-04.txt
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Thanks Michael,

Top posting. 
- for 261 I would at least include those arguments and make it clear when to use or the other
- so you don’t want to support the commonly used shortcut of specifying both and address and a prefix in one?
- 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. 

Cheers 
Ole

> On 25 Apr 2021, at 12:40, Michael Richardson <mcr+ietf@sandelman.ca> wrote:
> 
> 
> otroan@employees.org wrote:
>> Do you want to say anthing about tag 261 or perhaps subsume tag 261
>> into this?
> 
> Hi, I wasn't happy with tag 260/261.
> In addition to not distinguishing between v4 and v6 explicitely, tag 260 also
> confused 6-byte ethernet into the definition, and did not accomodate 8-byte
> ethernet.
> Tag 261 (on prefixes), I did not understand, which is why I wrote the document.
> 
>> Why do you have "Trailing zero bytes MUST be omitted." as it seems the
>> decoder would happily deal with trailing zeros?
> 
> Yes, well Postel rule definitely applies here.
> 
> For prefixes, a concern was expressed that irrelvant bits could be included
> and could form some kind of intentional convert channel.  Worse, they could
> be a non-intentional leak of private information (a la Heartbleed).
> So, it might be good to be able to make sure that encoders were more conservative.
> 
> --
> Michael Richardson <mcr+IETF@sandelman.ca>   . o O ( IPv6 IøT consulting )
>           Sandelman Software Works Inc, Ottawa and Worldwide
> 
> 
> 
>