Re: A problem with RFC 6465's Uniform Format for Extension Headers

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

On 04/02/2014 09:47, Hagen Paul Pfeifer wrote:
> * Fernando Gont | 2014-01-30 22:02:50 [-0300]:
> 
>> Folks,
>>
>> Mike Heard noted that the Uniform Format specified in RFC 6465 can't
>> possibly work.. and after giving some thought about it, it turns out
>> that implementing it would hamper the deployment of new transport protocols.
>>
>> We've written a short I-D that discussed the problem, and that proposes
>> an alternative, such that we achieve the same goal without possibly
>> messing with our Transport friends. :-)
> 
> Hey Fernando, I realized that too and wrote an I-D (back in July 2011):
> 
> http://tools.ietf.org/html/draft-pfeifer-6man-exthdr-res-01
> 
> Compared to your solution I propose to reserve a range.

Either solution works, but the firewall implementors might
have a preference one way or the other. RFC 7045 says
"Therefore, it is important that forwarding
nodes that inspect IPv6 headers be able to parse all defined
extension headers and deal with them appropriately,..."
So the question is whether they would find a reserved
range or a subtype easier to parse.

     Brian