Who is active as DHCP server in the network?
If it is Unleashed master AP and you have just one Unleashed AP in the network, rebooting AP will delete the lease, but if you have more than one AP in the network (at least one Unleashed AP online all the time and not rebooting all APs together) then existing master AP will maintain the lease.
If you have an external DHCP then AP has nothing to do with its lease time, AP will simply forward the traffic when client will reconnect after AP reboot and DHCP server should give the same lease (If previous lease maintained by DHCP server and still not expired).
Syamantak Omer
Sr.Staff TSE | CWNA | CCNA | RCWA | RASZA | RICXI
RUCKUS Networks, CommScope!
Follow me on LinkedIn