Subject: [dhcwg] Lease Query Draft Status/Comments

From: Greg Kilfoyle <[email-masked]>
Date: 01 Oct 2003 17:28:52 -0700

Hi,

I was wondering about the status of this draft since it expired
yesterday. Is there more work that needs to be done, or does it need to
be moved forward in some way (maybe both)?

Also, I was wondering if there could be a reduction in the number of
messages between relay and server in certain situations...

Upon reboot of the relay, I could see the need to gather all information
from the server(s) for subnets under the control of the relay. It may
also be that the relay is only interested in active leases. With the
current draft, this means 'walking' all relevant subnets that are
configured on the relay.

For example, the relay is configured to act as a relay for a class C
(/24) subnet. The server is configured to hand out only 100 addresses
from this subnet (for whatever reason). The server has handed out 50
addresses from the 100 allocated. In addition, the relay is only
interested in knowing about active leases.

With the current method, the relay will need to send 254 lease-query
messages (ignoring network and broadcast addresses) to the server, to
find out that there are 50 active leases.

To minimise relay<->server interaction, the relay could start with the
lowest IP address in the subnet and use a special flag or new option to
pass back the next in-use (i.e. with active lease) IP address. This
option/flag could also indicate that there are no more active leases.
Using this technique, the relay would only have to send 50 or 51
lease-query messages to the server to obtain all the information it
requires.

Cheers, Greg.
-- 
Greg Kilfoyle <[email-masked]>

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From: "Bernie Volz" <[email-masked]>
Date: Thu, 2 Oct 2003 10:16:46 -0400

Or, the relay could just query when it was necessary for a particular
address? If the relay sees a packet for an IP address it does not know
anything about, it can query the server for the address (to reduce delays,
the relay could allow the packet through until it learns what it needs from
the server or until some timeout expires). While this increases the logic
needed on the relay, it does avoid unnecessary queries (such as scanning an
entire subnet when perhaps only a few addresses are actually active).

- Bernie Volz

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf Of Greg
Kilfoyle
Sent: Wednesday, October 01, 2003 8:29 PM
To: [email-masked]
Subject: [dhcwg] Lease Query Draft Status/Comments

Hi,

Cheers, Greg.

---

From: Greg Kilfoyle <[email-masked]>
Date: 02 Oct 2003 07:47:52 -0700

Hi Bernie,

Not all environments can use the 'wait-for-traffic' approach.

Consider a situation where no traffic will pass unless various
host/routing tables are populated and/or virtual circuits are created.
In this case the full set of lease information must be obtained
immediately after reboot to correctly 'provision' all the circuits on
the access concentrator.

I can see that the draft has been written with a mind to the approach
you are talking about, but that's just one scenario.

Cheers, Greg.

---

From: Ted Lemon <[email-masked]>
Date: Thu, 2 Oct 2003 10:41:49 -0500

> you are talking about, but that's just one scenario.

Greg, I see your point, but this draft needs to get kicked out the 
door.   We could propose updates to it until the sun freezes, and 
indeed that's been what's happened to it quite a bit over the past five 
years.   What you need is related to leasequery, but does not need to 
be in this draft.   The right solution to your problem is to write up a 
new draft that describes a protocol that provides the functionality you 
need.   The protocol could easily be based on leasequery, or it might 
make sense for it to be a tcp protocol, given that you want to stuff a 
lot of data down the wire.   You might want to look at how failover 
does things.

---

From: Greg Kilfoyle <[email-masked]>
Date: 02 Oct 2003 09:01:25 -0700

Agreed...I came in late in the game; and I can work with the existing
specification.

What's needed to get the current draft moving then?

Cheers, Greg.

On Thu, 2003-10-02 at 08:41, Ted Lemon wrote:
> <excerpt><fixed>I can see that the draft has been written with a mind
> to the approach
> 
> </fixed></excerpt><fixed>
> 
> </fixed>Greg, I see your point, but this draft needs to get kicked out
> the door.   We could propose updates to it until the sun freezes, and
> indeed that's been what's happened to it quite a bit over the past
> five years.   What you need is related to leasequery, but does not
> need to be in this draft.   The right solution to your problem is to
> write up a new draft that describes a protocol that provides the
> functionality you need.   The protocol could easily be based on
> leasequery, or it might make sense for it to be a tcp protocol, given
> that you want to stuff a lot of data down the wire.   You might want
> to look at how failover does things.

---

From: Kim Kinnear <[email-masked]>
Date: Thu, 02 Oct 2003 17:42:15 -0400

>Agreed...I came in late in the game; and I can work with the existing

        Thanks Greg.  Ted said it better than I would have.  We
        need to move this draft along.  That said, Rich Woundy
        and I have several times explored approaches to extending
        leasequery to allow an access concentrator to receive
        information concerning all currently "interesting" or
        even "active" leases in a concise way (i.e., not based on
        reacting to current traffic through the concentrator).

        I would be happy to discuss the ideas that we have had
        with you, and to work with you (in any of several
        possible ways) to incorporate them into another draft
        extending leasequery (if that appears to be a reasonable
        approach to meeting your needs).

        But we need to get this existing draft turned into an RFC
        ASAP.

>What's needed to get the current draft moving then?

        Darn fine question, and it was already on my list of
        things to sort out with Ralph as the deadline for the
        need meeting approaches.  I'll do so soon, and let you
        (all of you) know.

        Cheers -- Kim