Env: Two Windows 2012 R2 DHCP servers in active/passive (hot standby) mode serving one scope. Scope lease duration: 1 day. MCLT: 1 hour.
Situation: New dhcp client gets IP configuration with a lease duration of 1 day. Upon release, then renew (prior to lease end, as a test) a new IP lease is obtained. However, its duration is 1 hour. Client is always reporting the same DHCP server (primary).
Why is the new lease 1 hour? 1 hour is coincidentally the same as the MCLT, which if I understand correctly is only invoked during a failover condition. No such failover has occurred here.
[Note: I removed the Failover configuration from this scope and the client picks up the correct scope lease time of 1 day.]