Subject: RE: DHCPv6 Relay Changes

From: Bernie Volz <[email-masked]>
Date: Mon, 23 Oct 2000 15:39:20 -0400

>I've been looking at relay agents with my DHCPv4 hat on.  In
>DHCPv6, the relay agent forwards messages to a multicast group that
>includes all DHCP servers.

Well, this is technically INCORRECT. My reading of the specification says
that DHCPv6 relays may forward using a number of mechanisms:
	- some combination of the FF05::1:3 (All Servers) site-local
multicast address
	- some other (perhaps a combination) of site-local multicast
addresses set up within the DHCP domain to include the servers in that
domain
	- or a list of unicast addresses for servers
(See section 8.3).

So, in this respect I think DHCPv6 relays are similar to DHCPv4 relays -
just that Multicast can be used instead of necessarily having to
pre-configure a relay with full server information.

The text doesn't explicitly allow for relay chaining (at least that I could
find).

- Bernie

-----Original Message-----
From: Ralph E. Droms [mailto:[email-masked]]
Sent: Monday, October 23, 2000 6:55 AM
To: DHCPv6 discussion list
Subject: Re: DHCPv6 Relay Changes

On Mon, 23 Oct 2000, Thomas Narten wrote:
> What is the benefit in allowing recursive enacapsulation through
> multiple relay agents? Would it make sense to simplify things and
> simply say there can be at most one relay agent in the path, and the
> relay agent always forwards the packet to a DHCP server (or an entity
> that looks like the server from a protocol perspective)?

Oops.  I've been looking at relay agents with my DHCPv4 hat on.  In
DHCPv6, the relay agent forwards messages to a multicast group that
includes all DHCP servers.  So, a relay agent will always forward DHCP
messages directly to a DHCP server...

- Ralph

---

From: "Ralph E. Droms" <[email-masked]>
Date: Mon, 23 Oct 2000 16:54:16 -0400 (EDT)

Whoops, That's what I get for answering from memory rather than reading
the spec.

In any event, we could make a design decision to disallow relay agent
chaining...

- Ralph

---

From: Jim Bound <[email-masked]>
Date: Mon, 23 Oct 2000 23:29:17 -0400

>In any event, we could make a design decision to disallow relay agent

I vote for that and its a good idea.

/jim