Subject: RE: Discussion Item - Reconfiguration in DHCPv6 (Items 8, 9, 18 o n Co nference Call Agenda)

From: Bernie Volz <[email-masked]>
Date: Fri, 8 Sep 2000 08:19:57 -0400

Jim:

OK. I was just wondering whether it was possible ... it would reduce
security issues as we push them off to the router advertisement messages.
Agreed that they are going to be useful if there are no routers (and perhaps
even if there are to effect transitions more quickly).

BTW: If there are no router advertisements received (after some period), I
assume a IPv6 host is supposed to attempt stateful address configuration (by
default).

- Bernie

-----Original Message-----
From: Jim Bound [mailto:[email-masked]]
Sent: Thursday, September 07, 2000 11:44 PM
To: DHCPv6 discussion list
Subject: Re: Discussion Item - Reconfiguration in DHCPv6 (Items 8, 9, 18
on Co nference Call Agenda)

Hi Bernie,

I have been thinking about this a lot and know very well what is needed
for IPv6 deployment.

I think we MUST permit Reconfigure and Reconfigure-Init with Multicast
to support site renumbering operations where stateless address
configuration is not used by the site.  It will permit a dhcpv6 server
to tell clients come get your new prefix NOW.  And in the response begin
the deprecation of old addresses.    

regards,
/jim

---

From: Jim Bound <[email-masked]>
Date: Fri, 08 Sep 2000 10:14:24 -0400

Bernie,

>even if there are to effect transitions more quickly).

Two things:

1.  I am not saying there are no routers on the LAN where clients exist
but something much more important as an assumption and important we
consider the assumption:

    Network Admins may not want to use stateless addrconf for 
    address configuration  but will have all routers set the M 
    bit in router advertrisements and tell clients go do address
    configuration with DHCPv6.  Its a customer/user policy decision
    to not use stateless addrconf on purpose.  We need to be prepared
    for that policy as we enhance DHCPv6 as a working group.

2.  If anyone wants to add to any of the Neighbor Discovery packets 
    they must go propose this in the IPng Working Group.  Like Mobile
    IPv6 has done.  We can't do that here the expertise is not wide
    enough on this list or enough of a quorum of IPv6 Neighbor 
    Discovery implementors (I think we only have Tim, Erik, Francis,
    and I as a note)????  And I think it should be done on IPng as 
    IETF policy IMO.

>assume a IPv6 host is supposed to attempt stateful address configuration (by

It has been left unspecified if there are no router advertisements so
that means if a client does not hear from a router our implementation
will go look for a dhcpv6 server, once we nail this spec down of course.

But if there are router advertisements I read the specs that an
implementaiton should not go look for DHCPv6 server unless the M bit is
set or the O bit (INFORM) is set.

regards,
/jim

---

From: Thomas Narten <[email-masked]>
Date: Mon, 25 Sep 2000 10:17:36 -0400

Responding to some very old mail...

> assume a IPv6 host is supposed to attempt stateful address configuration (by

RFC 2462 sez:

5.5.2.  Absence of Router Advertisements

   If a link has no routers, a host MUST attempt to use stateful
   autoconfiguration to obtain addresses and other configuration
   information. An implementation MAY provide a way to disable the
   invocation of stateful autoconfiguration in this case, but the
   default SHOULD be enabled.  From the perspective of
   autoconfiguration, a link has no routers if no Router Advertisements
   are received after having sent a small number of Router Solicitations
   as described in [DISCOVERY].

Thomas