Subject: Re: [PATCH] net: ipv6: Allow netlink to set IPv6 address scope

From: Brian Haley <[email-masked]>
Date: Mon, 17 Oct 2011 17:32:06 -0400

On 10/16/2011 10:26 PM, Lorenzo Colitti wrote:
> RFC 3879 deprecated site-local addresses because the were non-unique and thus
> ambiguous, and if they leak, they cause problems. This is not an issue
> in the use
> case I presented, because the addresses are syntactically global
> addresses - they
> just don't have global reachability.

Not very global then :(

>> The MIF problem statement (in the RFC editor's queue) talks about this problem,
>> http://tools.ietf.org/html/draft-ietf-mif-problem-statement-15 - perhaps it's
>> better to work there to develop a more generic solution (using DHCPv6, RA
>> options, etc) before making this change?
> 
> I don't think it's a good idea. Waiting for an IETF working group to
> produce a standard
> when it doesn't even have a problem statement finalized could take years.

It would be useful to give some input there, even if the Linux-specific
implementation of any standard plays with bits in the ifaddr.

> Is there another reason why we shouldn't enable userspace to do what it wants?

In my opinion it just feels like a hack, because things won't work when your
wifi attaches to a walled garden, or there's a third interface - who wins the
tiebreaker?

I do see your point that it will help with the problem you're trying to solve,
hopefully someone else will offer their opinion.

-Brian