Subject: WG consensus action: ACCEPT LL34 better transition to routable from v4LL using DHCP

From: Erik Guttman <[email-masked]>
Date: Tue, 23 Sep 2003 12:14:51 +0200

Action: Accept the issue, with the text as modified during discussion

New text:

2.11  Transition from Link-Local IPv4 to Routable Address

As discussed in Section 1.7, use of a routable address is preferred to
assignment of a Link-Local IPv4 address.  A Link-Local IPv4 address can
be configured due to transient failures, such as incomplete link-layer
authentication, spanning tree convergence issues, or because a DHCP
server failed to respond to an initial query, or is inoperative for some 
time.

Where a Link-Local IPv4 address is assigned due to a transient failure,
experience has shown that five minutes (see Appendix A.2) may be
too long an interval to wait prior to attempting to configure with DHCP.
This document does not specify a strategy for quickly recovering a
routable address in situations where a Link-Local IPv4 address is
assigned due to a transient failure.  In situations where many hosts are
present on a single subnet, frequent attempts to contact the DHCP server
could result in a heavy traffic load.  Further discussion of this issue
is provided in [DNAv4].

[DNAv4]
Aboba, B., "Detection of Network Attachment (DNA) in IPv4",
draft-ietf-dhc-dna-ipv4-01.txt, Internet draft (work in progress),
September 2003.

---

From: Robert Elz <[email-masked]>
Date: Wed, 01 Oct 2003 02:07:12 +0700

Date:        Tue, 30 Sep 2003 13:46:35 -0500
    From:        Ted Lemon <[email-masked]>
    Message-ID:  <[email-masked]>

  | A device that implements both IPv4ll and a DHCPv4 client MUST NOT alter 
  | the behavior of the DHCPv4 client to accommodate the IPv4ll state 
  | machine.

That's too much, for two reasons.   First, we don't specify how implementers
implement the specifications, just the end results - so that's inappropriate
right from the start.   Second, if I want to alter my dhcp client, to
have the LL address generation done by it, as well as dhcp address aquisition,
why shouldn't I?    Or if I just want to provide info from my dhcp client.

I know those aren't the kinds of modifications you're concerned about, but
they're covered by that blanket exclusion.

If anything needs to be said, all it needs to be is that the DHCP state
machine is not altered by LL.   That's it.

kre