DHCPv6 Client Configuration

Daniel Le daniel.le at exfo.com
Wed Oct 28 17:46:26 UTC 2009

David, thanks a lot for your help. I appreciate it.

WRT support of multiple addresses, I was confused by or perhaps I
misinterpreted the release notes of ISC DHCP v4.1.0p1 at
http://oldwww.isc.org/sw/dhcp/dhcp4_1_rel.php?noframes=1, which say:

There are a number of DHCPv6 limitations and features missing in this
release, which will be addressed in the future: 

Only Solaris, Linux, FreeBSD, NetBSD, and OpenBSD are supported. 
Only a single address is supported per IA.


-----Original Message-----
From: dhcp-users-bounces at lists.isc.org
[mailto:dhcp-users-bounces at lists.isc.org] On Behalf Of David W. Hankins
Sent: Wednesday, October 28, 2009 1:11 PM
To: Users of ISC DHCP
Subject: Re: DHCPv6 Client Configuration

On Fri, Oct 23, 2009 at 12:21:35PM -0400, Daniel Le wrote:
> Could someone please give an example of how to configure DHCPv6 Client

> for the options Authentication "keyinfo",

We don't currently support Authentication, tho it's on our agenda.
For my part I am mostly resisting authentication related code until we
have a framework I think operators can really use realistically (at
least a plan to solve the key distribution problem).

It is coming.

> Rapid Commit, and the
> statements to cover multiple client network interfaces within the same

> client host/system? A sample/snapshot of DHCPv6 client configuration 
> file dhclient.conf would be very nice.

For this, in the source distribution, see doc/examples/, there's a
sample config for client and server.

In a future release we will probably send rapid-commit by default, so
that the server operator selects whether rapid-commit is used or not,
but for now there is a sample config snippet for clients to send it.

Probably system integrators should use that in their default configs.

Just list multiple interfaces on the command line (or start one daemon
per interface, but in this case you want to give different -lf and -pf
flags for separate lease and pid files).

> Also, to configure multiple IPv6 dynamic addresses on a same 
> interface, I understand one way is to use an IA that contains multiple
> However since the current ISC DHCP production release 4.1.0.p1 only 
> supports a single address per IA, can we configure a client interface 
> to be associated with multiple IAs, thus letting it have multiple 
> addresses?

This shouldn't be true, the dhcpv6 client should support multiple
IAADDRs in any IA_NA or IA_TA (also multiple IAPREFIXes in any IA_PD).

The DHCPv6 server has a configuration knob so the operator can indicate
how many addresses the client should get.  Presently the "way to select
what addresses a client should get" is pretty lame, and the server will
give one from each pool until it satisfies the configured address count
(so you are limited to one pool per prefix).

Anyway, if it doesn't work, it's a bug.

David W. Hankins	"If you don't do it right the first time,
Software Engineer		     you'll just have to do it again."
Internet Systems Consortium, Inc.		-- Jack T. Hankins

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