Hi yahya01,
You can use iDRAC Setting Utility for initial configuration of iDRAC. Reboot the server and press "F2" during POST. From there you can configure iDRAC IP address and also configure iDRAC to use LOM1 for communication. For more details refer "Setting Up iDRAC IP Using iDRAC Settings Utility" section of iDRAC7 User Guide. User Guide is available at following link
ftp.dell.com/.../integrated-dell-remote-access-cntrllr-7-v1.30.30_User%27s%20Guide_en-us.pdf