Hack/modification to enforce minimum time?

[Oscar Ricardo Silva]

Not sure if I'll describe this properly ... we're considering a modification of
the dhcp server code to add extra time to the lease so it's completely not
available for an amount of time after lease expiration.  Before going forward
with this we'd like to know if anyone has already worked on this or implemented it.

We have several public networks that have a lot of churn, lots of users coming
and going.   Client A comes along, requests an address, gets address 1.2.3.4,
the lease time is set to an hour but the client leaves after being on for only
10 minutes so he issues a release.  Let's say our accounting software refreshes
its records every 20 minutes.  Since Client A issued the release, the address is
marked as available.  Client B comes along, requests and address, gets 1.2.3.4.
  As far as our accounting records go, we still think Client A is using address
1.2.3.4.  We want to enforce the lease time (or maybe half the lease time) so
that an address is marked as unavailable during either the lease time or half
the lease time.  That way, when client B comes along, even though address
1.2.3.4 is marked as released, it's still in the original lease time so client B
has to be assigned another address.


Clear as mud?  Any information would be appreciated.


Oscar