Subject: Re: Node Requirements: Issue 15 - IPv6 RA Flags Option (RFC 5075)

From: Alexandru Petrescu <[email-masked]>
Date: Fri, 28 Aug 2009 14:26:40 +0200

Thomas Narten a écrit :
> Tim Chown <[email-masked]> writes:
> 
>> There's a couple of newish RA-related RFCs out that may be relevant, 
>> though one is experimental: RFC 5006 (perhaps relevant in 6.2.2 of 
>> the node requirements draft) and RFC 5075.
> 
> We should mention RFC 5075/5175.
> 
> I came up with some text while thinking about this document a while
> back, but I can't find it right off.  Oh. I alredy snuck it into the
> document! :-)
> 
> 
> Does the following make sense:
> 
>    5.3.  IPv6 Router Advertisement Flags Option - RFC 5175
> 
>    Router Advertisements include an 8-bit field of single-bit Router
>    Advertisement flags.  The Router Advertisement Flags Option extends
>    the number of available flag bits by 48 bits.  At the time of this
>    writing, 6 of the original 8 bit flags have been assigned, while 2
>    are available for future assignment.  No flags have been defined that
>    make use of the new option, and thus strictly speaking, there is no
>    requirement to implement the option today.  However, implementations
>    that are able to pass unrecognized options to a higher level entity
>    that may be able to understand them (e.g., a user-level process using
>    a "raw socket" facility), MAY take steps to handle the option in
>    anticipation of a future usage.
> 
> I really don't think we should require folks implement this option,
> given it is not yet in use, and it may be years before any such bits
> are assigned.

Well let me say that I do currently use a flag in this option of
rfc5175. The bit is called 'M' and is the first to the left. It is
implemented in radvd under linux.  The code will probably never (or
when?) see the day out... but there it is.

(I never know whether we should tell IETF all we're doing, or not).

Alex