Re: Connecting to remote IPv6 addresses from Linux machine requires local scope id

On 7/24/06, Vlad Yasevich <[email protected]> wrote:
>
> On Mon, 2006-07-24 at 18:36 +0530, Dhiren Chandvania wrote:
>
> > Issues that I have:
> >
> >
> >
> > I]
> >
> > All outbound traffic from a Linux machine needs scope id. Why?
>
> Because linux does not implement the concept of "default interface".  If
> you only have link-local addresses (the ones that start with fe80:) then
> you always have to specify a scope id.  If you configure addresses with
> larger scope, you will _not_ need to always use scope id.
>

You always have to specify a scope id when you are using a link-local
address, because the SAME link-local address might be used by different
machines in different links (e.g., you are connected to multiple links - you
might find that one machine in each of those links is using that link-local
address). This ambiguity thus is resolved when you specify which interface
you want to send your message to.

Now, a question I have: for site local addresses, windows machines know
which interfaces to forward the packets to, based on matching the "site ID"
(it forwards packets out on all interfaces for which the "site ID" is the
same as that on the incoming interface). For linux, how does it solve the
same problem, i.e., knowing which interfaces are considered to be still
within the same site, and which are not?  thanks

-- 
Dr. Daniel Wong
Assistant Professor
Malaysia University of Science and Technology
** check out my book on wireless IP at
http://www.must.edu.my/~dwong/book.html **