Subject: Addresses and other parameters in Advertise and Solicit

From: Ralph Droms <[email-masked]>
Date: Thu, 26 Jul 2001 16:43:13 -0400

Bernie Volz wrote:

>1. In Section 14.3.1 (Creation and sending of Request messages), there
>    is no mention of using any of the "information" supplied by a
>    server in the Advertise message (in response to a Solicit). In
>    DHCPv4, the client sent information received in the Offer. We
>    probably should be explicit about this and perhaps even suggest
>    that the information received by a client in an Advertise is
>    basically for information purposes only to help it determine
>    whether this server will offer it what it needs.

So, are you suggesting that the DHCPv6 client Request exactly the addresses 
and options from the Solicit, or no addresses or options, or ???

>    Perhaps the
>    addresses assigned in the Advertise should even just be prefixes
>    (interface portion all 0's)?

I don't have a strong feeling one way or the other.

>    If instead we want the server to assign "real" addresses, should
>    something be said about how long those should be valid and whether the
>    server should attempt to assign those same addresses to the client in
>    a subsequent Request/Reply exchange for the IA? Perhaps we could punt
>    and say this is a server implementation issue (whether it assigns real
>    addresses and whether those are held for some (short) time for the
>    client)?

I take "valid" in this context to mean "reserved for this client".  Has 
this scenario been a problem in DHCPv4?  Do we need to specify any more 
mechanism than we have in the DHCPv4 spec?

>    NOTE: If real addresses are returned, perhaps a client might even
>    initiate DAD during the Request/Reply in which case it can do these
>    two items in parallel (though this would be somewhat tricky since it
>    would not want to Decline the addresses before receiving the Reply).

Hm.  I guess I had anticipated that the client would do DAD and either 
Request or Decline the addresses in the Advertise.  It is the case that the 
spec does not constrain the times at which a Decline can be sent.  I'm not 
sure it makes much sense for the client to Request a set of addresses and 
then Decline them later.

- Ralph