Dell OptiPlex 980 (Early 2010) - Manual (Page 19)

1. DHCP Mode
Under Wired LAN IPv4 Configuration, select DHCP Mode and press Enter.
The TCP/IP Settings menu changes to the Wired LAN IPv4 Configuration page.
ENABLED: If DHCP Mode is enabled, TCP/IP settings will be configured by a DHCP server. More options will be displayed on
the screen. Select ENABLED and press Enter, no additional steps are required.
DHCP mode enabled.