DHCP clients losing address / backdated lease date

[Nicolas C.]

Hello,

We have several cases of linux or windows clients loosing their IPv4 
address.

We noticed that sometimes, the date the client is supposed to have 
obtained the lease is way in the past (like in the year 1876).

The version of DHCP is 4.2.2 (Debian Wheezy), two DHCP are in failover. 
We suspect some security features on the ethernet switches but they have 
been deactivated.

Is anyone experienced this behavior?

Regards,

Nicolas