Subject: RE: DHCPv6 address model proposal...

From: Bernie Volz <[email-masked]>
Date: Thu, 14 Sep 2000 15:31:09 -0400

In agreement with the two basic requests.

The first (Associate some IP addresses with this IA) request is really lease
me some addresses (or lease me what addresses I might have had in the past)
and the second is the renewal request.

We did have some open issues with these requests that were under discussion.

- I believe we all agreed that allowing the client to supply a list of
prefixes for addresses the client wanted is allowed. The server can supply
additional addresses and might not assign addresses for all supplied
prefixes.

- I believe the renewal was a bigger issue because it wasn't clear whether a
client could "renew" an individual address or had to renew all of them. The
issue also required us to resolve whether lifetimes are per address or per
IA, which was never fully resolved. As with router prefix advertisements, I
personnally feel that the lifetimes should be per address, not per IA (ie,
the "lease" each address includes per address lifetimes, rather than a
single lifetime for all addresses).

The way the list of requests below reads ("renew this IA") kind of implies
that one leases IAs and not addresses. Perhaps you've implied to solve the
problem by saying all addresses for an IA have the same lifetimes?

- Bernie Volz

-----Original Message-----
From: Ralph Droms [mailto:[email-masked]]
Sent: Thursday, September 14, 2000 2:46 PM
To: DHCPv6 discussion list
Subject: Re: DHCPv6 address model proposal...

At 11:16 AM 9/14/00 -0700, you wrote:

> > A client can make two requests to a server about an IA:
> >
> > * Associate some IP addresses with this IA
> > * Renew this IA
>
>I thought we figured out that these were both the same request!   :'}

I took this from your original message:

>I think there are actually only two questions a client ever needs to
>ask the server: "please associate an IP address with this identity,"
>and "please renew the association for this identity."

We might have figured out the are both the same request in another message 
- I skimmed through all the messages pretty quickly and may have missed 
it.  In fact, I made a similar suggestion in another message:

>Well, suppose the client has just a single request it can make of the 
>server: here's an identity association (IA) identifier - tell me the IP 
>addresses (and associated lease lengths) associated with this IA.
>
>If the server has no record of the IA (a "new" request), it assigns some 
>addresses and returns them to the client.  If the server has previously 
>assigned addresses to the IA, it simply returns those addresses, with 
>(potentially) new lease lengths.  If the state of the IA has changed - 
>e.g., some of the previously assigned addresses are no longer valid - the 
>server returns the *current* addresses.

- Ralph

---

From: Jim Bound <[email-masked]>
Date: Fri, 15 Sep 2000 00:20:15 -0400

>additional addresses and might not assign addresses for all supplied

I believe we all agreed to this to?  

>single lifetime for all addresses).

Leases are for Addresses not IAs.  IAs are only identifiers that is
all.

>problem by saying all addresses for an IA have the same lifetimes?

This also removes the capability for a sever admin to give one address
it provides a client one lifetime and another address for a client a
different lifetime.

The other reason we need to have lifetimes per addresses is for
dynamic renumbering with DHCPv6.  After a reconfigure-init the server
can reduce the lifetimes of one of the addresses but extend or keep the
others to gradually fade out that particular address.  This is a feature
the current design supports that is important for one of the goals of
IPv6 to support dynmamic renumbering and one of IPng's goals in the
IETF. And dynamic renumbering is the key reason for reconfigure-init.

It seems we need to discuss this further.

regards,
/jim