Exponential Lease Time

[Glenn Satchell]

Nice to see something work out the way you want!

I was having a thought, and some platforms send DHCPINFORM requests from
time to time.

regards,
-glenn

On Fri, September 7, 2012 1:03 am, Nicholas F Miller wrote:
> I think you may have cracked it. Some initial testing shows it working as
> expected.
> _________________________________________________________
> Nicholas Miller, OIT, University of Colorado at Boulder
>
>
>
>
> On Sep 5, 2012, at 8:52 PM, Glenn Satchell wrote:
>
>> This is going to increment on every packet from the client, so perhaps
>> you
>> need to test for the request-type using option dhcp-message-type. See
>> dhcp-options man page for possible values. Perhaps only increment on
>> DHCPREQUEST type? So a big if statement around the sections that
>> increment
>> renewal.
>>
>> if option dhcp-message-type = 3 {
>>  if renewal = 3 {
>>    ...
>>  }
>> } else {
>>  default ....
>> }
>>
>> regards,
>> -glenn
>>
>> On Thu, September 6, 2012 2:31 am, Nicholas F Miller wrote:
>>> Here are some observations from my testing. The results are not
>>> consistent
>>> enough to be used in production but it is still pretty interesting.
>>>
>>> 1) I haven't seen one lease that had a renewal = 1. They all seem to
>>> start
>>> with a renewal = 2 (Windows and Mac clients, wired and wireless). This
>>> may
>>> be a result of using helper addresses on the routers and WISM2s.
>>> 2) iPhones seem to jump straight to the longest lease time (if renewal
>>> =
>>> 3).
>>> 3) Windows phones jump straight to the second longest lease time (if
>>> renewal = 2).
>>> 4) Android phones behave the same as Windows and Mac clients.
>>>
>>> Here are the values I used for my testing which were defined in the
>>> pool
>>> statement:
>>>
>>>        if renewal = 3 {
>>>                default-lease-time 86400;
>>>                max-lease-time 86400;
>>>
>>>        } elsif renewal = 2 {
>>>                default-lease-time 14400;
>>>                max-lease-time 14400;
>>>                set renewal = 3;
>>>
>>>        } elsif renewal = 1 {
>>>                default-lease-time 3600;
>>>                max-lease-time 3600;
>>>                set renewal = 2;
>>>
>>>        } else {
>>>                default-lease-time 900;
>>>                max-lease-time 900;
>>>                set renewal = 1;
>>>        }
>>>
>>> _________________________________________________________
>>> Nicholas Miller, OIT, University of Colorado at Boulder
>>>
>>>
>>>
>>>
>>> On Aug 31, 2012, at 2:42 PM, Norman Elton wrote:
>>>
>>>>> Out of interest, does processing that sequence of statements create
>>>>> more or
>>>>> less load than just processing renewals without dynamic lease lengths
>>>>> ?
>>>>
>>>> Definitely deserves further testing. We've done some scripting before
>>>> and it didn't contribute to a noticeable load.
>>>>
>>>>> Also, when the lease expires, does "renewal" stay set or does it get
>>>>> removed
>>>>> from the lease record ?
>>>>
>>>> After the lease expires, it appears that the "renewal" variable gets
>>>> wiped. Again, this could use some more testing.
>>>>
>>>> I pretty much hacked this up. I'd love some feedback from folks who
>>>> are more familiar with how the variables work and are designed to be
>>>> used.
>>>>
>>>> Norman
>>>> _______________________________________________
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>>>> https://lists.isc.org/mailman/listinfo/dhcp-users
>>>
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>>
>>
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