loophole with limiting leases per client

[Brian J. Murrell]

Ted, et. al.

Over the last few months we have undergone a considerable development
here to prevent address hoarding.  We give our customers a limted number
of addresses each based on a contracted service level.  The way we
decided to limit addresses was with a registration server.  Any/every
machine on the network would be given initially an address from a
"limited-routing" address space.  The size of this pool is for all
intents and purposes unlimited.  This temporary address would give them
the ability to contact the registration web server, log in and specify
the ethernet addresses that they would like to have "fully routed"
addresses for.  The dhcp server would then be populated with a host
entry for that ethernet address.

A situation seems to have arisen however.  If a given machine has a host
entry, it successfully gets a routed address, albeit a dynamic address
out of a pool.  The problem arises depending on whether the address is
bound to a client identifier (hereafter referred to as UID) or a
hardware address.  If a UID is present in the discover/request, the
address is bound to that.  If it is absent, it is bound to the hardware
address.  The latter case is just fine and does what we want.  However,
if the client sends a UID the address gets bound to that.  If the client
sends another request with a new UID, a new address is allocated and the
new UID is bound to the new address.  The problem in the case of this
client is that we are permitting him addresses based on his hardware
address being "known" but assigning addresses based on his UID, giving
him as many addresses as he wishes to ask for using different UIDs.

So how to solve?  I don't think the server has any way to deal with this
situation right now.  Please correct me if I am wrong.  I want to
propose a switch that governs the order of priority when searching for
and assigning leases.  Or how about, even simpler, a switch which tells
the server to only consider hardware addresses when searching for and
assigning leases?

Thots?


--
Brian J. Murrell                              InterLinx Support Services, Inc.
North Vancouver, B.C.                                             604 983 UNIX
        Platform and Brand Independent UNIX Support - R3.2 - R4 - BSD