Re: Joel Jaeggli's Discuss on draft-ietf-6man-ext-transmit-04: (with DISCUSS and COMMENT)

[joel jaeggli <[e-mail]>]

On Oct 8, 2013, at 12:45 PM, Brian E Carpenter <[e-mail]> wrote:

> Joel,
> 
> Would this help?
> 
> OLD
>   Today, packets are often forwarded not only by straightforward IP
>   routers, but also by a variety of intermediate nodes, often referred
>   to as middleboxes, such as firewalls, load balancers, or packet
>   classifiers.
> 
> NEW
>   Today, IPv6 packets are often forwarded not only on the basis of their
>   first 40 bytes by straightforward IP routing. Some routers, and a
>   variety of intermediate nodes often referred to as middleboxes, such
>   as firewalls, load balancers, or packet classifiers, inspect other
>   parts of each packet.
> 

I find that more palatable yeah.

> (and possibly some changes for consistency later in the document)
> 
>    Brian
> 
> 
> On 09/10/2013 08:22, joel jaeggli wrote:
>> On Oct 8, 2013, at 12:06 PM, Brian E Carpenter <[e-mail]> wrote:
>> 
>>> On 08/10/2013 20:19, Joel Jaeggli wrote:
>>> ...
>>>> ----------------------------------------------------------------------
>>>> DISCUSS:
>>>> ----------------------------------------------------------------------
>>>> 
>>>> This is a dicuss because I'd like to see if I'm in the rough in this.
>>>> 
>>>> Devices generally considered to be IP routers in fact are able to or find
>>>> it necessary to forward on the basis of headers other than the IP header
>>>> e.g. the transport header. By the definition applied in the problem
>>>> statement all ipv6 capable routers in the internet that  I'm aware are or
>>>> are capable of being middleboxes. 
>>> IMHO, yes, if a box is taking a forwarding decision on the basis of anything
>>> other than the first 40 bytes of an IPv6 header, then it's a middlebox
>>> as far as this draft is concerned. Any such box is not a "straightforward IP
>>> router".
>>> 
>>> In the process of working on the draft I have actually corresponded briefly
>>> with Steve Deering, and I'm pretty sure he would agree with me (with
>>> added expletives).
>> 
>> Right, so there are no IP routers on the internet today and you should update the document accordingly because as it stands now it seems to presume their existence.
>> 
>>>> I would welcome the existence proof of an ipv6 capable router which is
>>>> not capable of being a middlebox by the definition applied in the problem
>>>> statement.
>>>> 
>>>> I'm not sure that's a glaring flaw in the document but it certainly is
>>>> with our vocabulary around taxonomy if true.
>>>> 
>>>> 
>>>> ----------------------------------------------------------------------
>>>> COMMENT:
>>>> ----------------------------------------------------------------------
>>>> 
>>>> If you need to find the transport header due to configured policy and you
>>>> can't due to being unable to parse the extensions chain your configured
>>>> action will be to drop. That perhaps weasels it's way through section 2.1
>>>> requirements but it's still quite ugly.
>>> Yes, and it's the reason that the Internet is mainly opaque to IPv6
>>> extensions headers today.
>>> 
>>>   Brian
>>> 
>> 
>