Subject: RE: DHCPNACK for DHCPv6 [Proposed Draft Changes]

From: "Bernie Volz (EUD)" <[email-masked]>
Date: Wed, 18 Jul 2001 18:23:02 -0500

While moving this functionality to the Relays is certainly very interesting:
- Servers will need to do it anyway (what if no relays)
- Servers have more complete network knowledge. While a router may be a relay,
a relay does not have to be a router. Sure, the relay could look at the Router
Advertisements (or the hosts routing table) to see what prefixes are currently
valid.
- I think most vendors would rather have relays be relatively dumb?

And, (IIRC) I don't believe there is anything in the spec prohibiting it at
this point?

- Bernie

-----Original Message-----
From: Ted Lemon [mailto:[email-masked]]
Sent: Wednesday, July 18, 2001 7:09 PM
To: DHCPv6 discussion list
Cc: DHCPv6 discussion list
Subject: Re: DHCPNACK for DHCPv6 [Proposed Draft Changes] 

>   The format of "Error Code" option is not specified in the draft. It is
> needed to be included.

I think it goes into the IA option, but you're right - it needs to be
clarified.

>   It will be better, if this functionality can be incorporated in the
> agent,since, it is the only thing which knows well about the prefix in which
> the client message is received. And the advantage is, if this checking is
> done, this packet can be prevented from forwarding it to the multiple
> servers and save multiple processing time. The agent itself can send the
> NoPrefixMatch status directly to the client.

Ooh, good point!   I think it would be good if the agent could do
this, although I have to admit that I am concerned that some people
who implement relay agents may not want to have to delve into the IA
to validate a packet.   I'm in favor of doing as you suggest, but I
suggest that we defer to the working group to see if any router
vendors have a problem with this.

Also, the timing is a bit tight on making this change, and I wouldn't
blame the authors if they said "no, sorry, do this in a new draft."  I
think it's okay to make this optional, so doing it in a seperate draft
should be fine.

>   If the client is receiving the error status as NoPrefixMatch error, what
> may be the reason other than client's plugging in to different subnet. I
> agree that, some roghe server can send this status, but, it can be prevented
> by authentication.

The client may be mobile, and may be able to reach more than one
mobile access point.  The two access points may want to think of
themselves as seperate links, even though their physical link-layers
overlap.  I don't know how likely this is with existing technology,
but it's certainly been discussed with respect to 3G phones.  I think
it's important to leave the language open for this case.

			       _MelloN_

---

From: "Vijay Bhaskar A K" <[email-masked]>
Date: Thu, 19 Jul 2001 05:05:14 +0530

RE: DHCPNACK for DHCPv6 [Proposed Draft Changes]
  -----Original Message-----
  From: [email-masked] [mailto:[email-masked]]On
Behalf Of Bernie Volz (EUD)
  Sent: Thursday, July 19, 2001 4:53 AM
  To: DHCPv6 discussion list
  Subject: RE: DHCPNACK for DHCPv6 [Proposed Draft Changes]

  While moving this functionality to the Relays is certainly very
interesting:
  - Servers will need to do it anyway (what if no relays)
  - Servers have more complete network knowledge. While a router may be a
relay,
  a relay does not have to be a router. Sure, the relay could look at the
Router
  Advertisements (or the hosts routing table) to see what prefixes are
currently
  valid.
  [Vijay Bhaskar A K] ***********

  I think, the relay needs to know at what interface the packet is received.
Using that, it can tell prefix is matching or not, i guess.
  - I think most vendors would rather have relays be relatively dumb?

  And, (IIRC) I don't believe there is anything in the spec prohibiting it
at
  this point?

  - Bernie

  -----Original Message-----
  From: Ted Lemon [mailto:[email-masked]]
  Sent: Wednesday, July 18, 2001 7:09 PM
  To: DHCPv6 discussion list
  Cc: DHCPv6 discussion list
  Subject: Re: DHCPNACK for DHCPv6 [Proposed Draft Changes]

                                 _MelloN_

---

From: Jim Bound <[email-masked]>
Date: Thu, 19 Jul 2001 00:54:02 -0400 (EDT)

reading mail sequentially to catch up (did something besides ipv6 for an
evening I feel guilty though) and that is where I was going.  I would say
stateless instead of dumb though :----)

/jim