Re: [dhcwg] lease query question

> Would replacing the current problem statement with this one
> suggested by Ralph be sufficient to meet (enough of) your
> concerns to allow the draft to proceed?

Not really.

What we had originally (I had thought) was is a relatively simple
problem, with a relatively simple solution, and one that didn't really
change DHC in any serious way. The solution seem to have taken on
feature creap, where the problem got expanded, and the solution got
expanded. Sure, given any solution, one can go back and rewrite the
problem statement to make it match the solution. While that is
certainly necessary to make the document accurate, I have to wonder
whether the problem statement actually makes sense or is well defined.

> >        Router-type devices which want to enforce some level of access
> >        control over which IP addresses are allowed on their links
> >        need to maintain information concerning IP<->MAC/client-id
> >        mappings.  One way in which these devices can obtain
> >        information about IP<->MAC/client-id bindings is through "DHCP
> >        gleaning", in which the device extracts useful information
> >        from DHCP messages exchanged between hosts and DHCP
> >        servers.

So far, simple.

> >        However, these devices don't typically have stable storage
> >        sufficient to keep this information over reloads.  There may
> >        be additional information that is useful to the device that
> >        cannot be obtained through DHCP gleaning.  The leasequery
> >        request message described in this document allows a device to
> >        obtain information about IP<->MAC/client-id bindings from a
> >        DHCP server.  This information may include currently active
> >        bindings, bindings involving previously assigned addresses for
> >        which the lease on the address has expired and static bindings
> >        for devices that are otherwise configured and not using DHCP
> >        for address assignment.

Note, that above is pretty vague and doesn't say what information the
access device needs. It's hard to look at the problem statement and
say "yes, I understand the boundaries of the problem" and then "and
the solution seems like a good match for the problem".

Popping up a level, how is it even appropriate for the DHC WG to be
doing work on "access control in router type devices"? One can argue
that work of this broad a scope is well out-of-scope for this WG
(e.g., look at the recently approved charter). I'm far from clear that
work of this scope should be done in DHC or that the problem is well
enough understood to conclude that DHC lease query is the right
solution or that any DHC-based solution is the right one.  What about
routers wanting to do access control that don't use DHC, for instance?

And note, I'm not raising these issue just to be a PITA. These are
questions that I expect that the IESG would ask if I brought the
document forward. Thus, I need to have reasonable responses to those
questions. Otherwise, I can predict the likely outcome.

Thomas
_______________________________________________
dhcwg mailing list
dhcwg@ietf.org
https://www1.ietf.org/mailman/listinfo/dhcwg