deering at cisco.com
Sun Apr 29 14:10:10 PDT 2001
At 4:24 AM -0400 4/29/01, J. Noel Chiappa wrote:
> > From: David.Eckhardt at cs.cmu.edu
> > one of the myriad forms of IPv6 address is some constant prefixed to
> > a 48-bit MAC address, which can somehow be parleyed into a globally
> > routable address.
>I gather IPv6 stateless configuration can do do this (the host gets the
>topologically significant high-order part of its globally-significant IPv6
>address from the network) - but I gather that the use of MAC addresses has
>recently been deprecated because of privacy concerns. In other words, you
>pick some random bits for the low order part, and proceed as above.
The IPv6 temporary addresses (with randomly-generated lowest-order
field) do not deprecate the ones generated from MAC addresses, but
rather augment them. I expect many IPv6 nodes to use both kinds of
- To accept communication initiated by others (e.g., when providing
the server side of a client-server style application, or accepting
incoming IP telephone calls, or participating in a peer-to-peer
style application), one wants a stable, globally-unique address,
usually with a corresponding entry in the DNS. The MAC-address-
derived IPv6 addresses are good candidates for that.
- When initiating communication to others (e.g., when acting as a
client in a client-server style app like the web), one may prefer
a less-long-lived address for privacy reasons. The IPv6 temporary
addresses are intended for that purpose.
A single IPv6 node may of course play multiple roles, and therefore
obtain both kinds of addresses (just like I want a stable phone number
for my phone so people can call me, but also the ability to hide that
number -- by suppressing caller-ID -- when I call others).
More information about the end2end-interest