How to set the IPv6 linklocal scope id for an interface?

[JINMEI Tatuya / 神明達哉]

At Thu, 17 May 2012 15:13:08 -0700,
prabhakar lakhera <prabhakar.lakhera at gmail.com> wrote:

> Removing the hyperlinks (these seem to get appended by gmail:
> 
> Hi,
> 
> Is there any way for the administrator to set an interface's scope if
> for link local scope?

I don't think it's been merged to *BSDs, but the original KAME
implementation contained a tool called "scope6config"
http://www.kame.net/dev/cvsweb2.cgi/kame/kame/kame/scope6config/

If I understand you correctly, that does what (at least superficially)
you asked.  From a quick look the kernel already seems to have the
underlying ioctl, so maybe you can simply fetch the source file of the
tool and compile it.

That said...

> I am trying to avoid the following:
> 
> Here's the problem. I have two interfaces A and B on same link. Both
> learn RA for the link. One of these is used to add a default route
> entry in the routing table. Lets say default router entry for A is
> picked, we have the following default route entry:

I'm afraid it's less likely that you can achieve this just by tweaking
the scope zone configuration.  I suspect there are other places in the
kernel where one-to-one mapping between interfaces and links are
assumed, either implicitly or explicitly, and you'll have another
trouble.

But that's a guess.  Maybe you should at least give it a try.  Good
luck:-)

---
JINMEI, Tatuya
Internet Systems Consortium, Inc.