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A DHCP server (dhcpd) is present but disabled on the OnBoard appliance by default. The OnBoard appliance administrator may want to enable the DHCP server to provide fixed IP addresses for connected devices that are running DHCP client software. The fixed IP addresses use the following DHCP features:
• Persistent leases, which allow the device on the private side of the OnBoard appliance to keep the same IP address even after the OnBoard appliance or the device is rebooted.
• Persistent storage of lease information, with the leases file and the dhcpd configuration files stored in the Flash memory and available to be optionally updated from time to time when dhcpd is enabled.
• Preconfigured leases: using the MAC address of the device, the OnBoard appliance administrator can assign an IP address to a client before the OnBoard appliance sees the device on the network.NOTE: IP addresses assigned to connected devices must remain constant over time because each device is assigned an IP address as part of its configuration on the OnBoard appliance. For that reason, the OnBoard appliance DHCP server should not be used to provide dynamic IP addresses to devices.The ability of DHCP to supply fixed addresses can be used to implement the addressing scheme for connected devices, which is described in the following sections of this manual:The OnBoard appliance administrator can enable the DHCP server and assign IP addresses to devices by logging into the OnBoard appliance command line as root and manually editing the /etc/dhcpd.conf file and performing other steps described under Configuring the DHCP Server. Before deciding whether to use the DHCP server to configure addresses for connected devices, the OnBoard appliance administrator should understand the available options for assigning IP addresses to connected devices, which are described in Address configuration for connected devices.