The command "lease 40" set the duration of the lease (the time during which a client computer can use an assigned IP address). The syntax is "lease {days[hours] [minutes] | infinite}". In this case the lease is 40 days. Therefore the server for the finance department is getting new IP address every 40 days. It is very inconvenient and we should assign/configure a static IP address for the finance department server. We can do it via two ways: + Static configure an IP address on the finance department server and exclude that IP address in the DHCP pool + Instruct the DHCP pool to assign a specific IP address for the MAC address of the finance department server (via the "client-identifier ..." or "hardware-address ..." command)