[v6ops] Layer violations, etc. [was draft-ietf-v6ops-ula-usage-recommendations - work or abandon?]

[Brian E Carpenter <[e-mail]>]

On 09/11/2015 01:06, Nick Hilliard wrote:
> On 08/11/2015 05:25, Lorenzo Colitti wrote:
>> On Fri, Nov 6, 2015 at 7:08 PM, Nick Hilliard <[e-mail]> wrote:
>>>    On 06/11/2015 00:20, Lorenzo Colitti wrote:
>>>>     It breaks any application that requires that the application know its
>>>>     source address. Examples are SIP, FTP, audio/video chat, etc.
>>     your argument is the wrong way around: some protocols deliberately
>>     introduce layering violations by demanding that transport identifier
>>     information is encoded at the application layer.  Transport identifier
>>     translation merely shows up this brokenness.  The brokenness is not
>>     with the translation mechanism but with the higher level protocols.
>>
>> Nope. Those protocols aren't broken, they worked fine for years until NAT
>> arrived and broke them. They still work fine on networks that operate the
>> way the Internet was originally designed with end-to-end connectivity.
> 
> NAT predates both sip and the vast majority of other protocols which encode
> inline transport layer identifiers (skype, other chat, etc).
> 
> Also, I hope you're not arguing that protocol layering violations are
> acceptable from a design point of view.

Ah, so you don't like TCP, either, then?

This is all very interesting (and why I wrote my rant last year,
https://www.cs.auckland.ac.nz/~brian/CCR-201404-IPaddrHarmful.pdf)
but I'm not sure what it has to do with the ULA draft, now we've established
that ULA+NPTv6 is not an IETF standard.

   Brian

> 
> You're correct that ftp predates nat but having said that, its layering
> violations were recognised from the earliest days of the internet as being
> atrocious protocol design because of the problems they caused.
> 
> Nick
> 
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