Subject: RE: IPv4 Scoped Address Architecture

From: Stuart Cheshire <[email-masked]>
Date: Thu, 17 Aug 2000 13:34:24 -0700

>It also helps if a host has only one interface, i.e., is NOT
>multihomed. For multihomed hosts, you run into the problem that
>when sending to a particular given link-local address, you don't
>know which interface to send the packet out on.

I think this is an API issue, not a protocol issue.

The problem is APIs that only allow you to specify the destination 
address for a packet or connection, instead of specifying a source 
interface and a destination address, or a source/destination address pair.

Stuart Cheshire <[email-masked]>
 * Wizard Without Portfolio, Apple Computer

---

From: Dale Worley <[email-masked]>
Date: Thu, 17 Aug 2000 17:44:15 -0400

From: Stuart Cheshire <[email-masked]>

Conversely, it's a side-effect of the fact that link-local addresses
are a newish feature of IP.  Historically, routing has always been a
problem, but there was always a "right" interface for any given
destination.

But this problem suggests caution if there is more than one network
"in the vicinity" using link-local addresses.  Ideally, no device
should have interfaces onto two networks that use the same space of
local addresses, unless the device is actively bridging them so that
colliding address assignments cannot happen.

Dale
-- 
Dale R. Worley    Engineer                  <[email-masked]>
Agranat Systems   Embedded Web Technology   http://www.agranat.com/