Regarding the dhcp lease time

[Bruce Hudson]

On Mon, May 13, 2019 at 08:46:46PM +0530, Murali Krishna wrote:
 
> In the current scenario client requested for the respective lease for the
> time duration as mentioned in the conf file.
> 
> Here is the sequence of flow it happened:
> 1. Client initiates DHCP Request for 3600s(1hr)
> 2. Server acknowledges(DHCP Ack) with lease time:(158253440s) 1831 days, 15
> hours, 17 minutes, 20 seconds
> 
> How the server is calculating the lease time which is not the one defined
> as per the conf file.

    I suspect your timeline is incomplete. Let me propose an alternative (for
which, I confess, I have no real evidence):

    1. Client initiates DHCP Request for 3600s(1hr)
    2. Server acknowledges this lease and records it in the lease file,
       ending at an absolute time of "now+1 hour".

    3. System admin sets the clock back 5 years. 

    4. Client initiates DHCP Request for 3600s(1hr)
    5. Server acknowledges the existing, still valid lease, ending at an
        absolute time the server sees as 5 years in the future.

    When you change the clock, are you deleting the existing lease database?
-- 
Bruce A. Hudson				| Bruce.Hudson at Dal.CA
ITS, Networks and Systems		|
Dalhousie University			|
Halifax, Nova Scotia, Canada		| (902) 494-3405