successful lease event trigger

Terry L. Inzauro tinzauro at
Thu Jun 11 11:03:03 UTC 2009

Niall O'Reilly wrote:
> Terry L. Inzauro wrote:
>> List,
>> Whats the best way to keep/record ALL lease activity?
>     It's not clear to me what your requirements are:
>     "best" for what purpose, "activity" in what sense?
>     The leases file shows the current state of all known dynamic
>     leases, but not that of leases which are unknown.  IIUC, a lease
>     becomes unknown which has at some time been, but no longer
>     remains, in the  server's configuration, as it is not written to
>     the leases file when this is updated.  If you need to record
>     leases from before the last significant configuration change,
>     you need to take account of this.
>     The logs show the recent history of lease activity, according
>     to how long you keep them.  This history will show transaction-
>     -level detail of activity relating to fixed addresses and to
>     unknown (no longer known) leases.  It will also show activity
>     relating to earlier history of currently known leases.
>     I think you'll find discussions both on processing logs and on
>     parsing the leases file in the archives of this list.
>     If you can express your purpose more clearly, you may find
>     either that a well-known solution is available or that there
>     are people on this list who are interested in working with you
>     to solve an outstanding problem.
>     Best regards,
>     Niall O'Reilly
>     University College Dublin IT Services

Well put.

I would define best as "most efficient and easy to maintain". I like to keep configuration as simple and close to standards
as possible.


I am trying to derive a method of retaining the MAC/IP combinations (and maybe other information) for all successful leases
for compliance and auditing  purposes.  Basically, in the public sector, I have to be able to tell law enforcement who (which
mac addres) had obtained an address and at what time (to the best of my knowledge).

At first I envisioned a script being ran upon a successful lease that would log various info to SQL or something like that.
I thought this method would be possible based on the section called 'REFERENCE: EVENTS' (in man 5 dhcpd.conf) but I am
finding a lack of documentation or examples on that particular subject.

Perhaps I am making something out of nothing. Is this problem simply a matter tuning syslog-ng to log all DHCPD related
messages to a log that is later archived indefinitely?

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