DHCP server persistence is the ability of the firewall save DHCP lease information and to provide the client with a predictable IP address that does not conflict with another use on the network, even after a client reboot.
DHCP server persistence works by storing DHCP lease information periodically to flash memory. This ensures that users have predicable IP addresses and minimizes the risk of IP addressing conflicts after a reboot.
DHCP server persistence provides a seamless experience when a user reboots a workstation. The DHCP lease information is saved, and the user retains the same workstation IP address. When a firewall is restarted, usually due to maintenance or an upgrade, DHCP server persistence provides the following benefits:
To configure DHCP Server Persistence, select the Enable DHCP Server Persistence check box. Optionally, you can modify how often the DHCP server stores DHCP lease information by modifying the DHCP Server Persistence Monitoring Interval field. The default is 5 minutes.