You can run below racadm command to take backup of iDRAC configuration in xml format and use it to reconfigure iDRAC later

     racadm get -f iDRACConfig.xml -t xml -c iDRAC.Embedded.1 --replace --includeph

To configure the iDRAC with same xml file you can run below command

     racadm set -f iDRACConfig.xml -t xml -c iDRAC.Embedded.1

Note : The iDRAC configuration file downloaded will have password hash for local users hence when you import it back all users will be recreated. Downloaded file will not have any other password like VNC, SMTP etc. If you need to set those values also as part of import you need to edit the downloaded file and add those password details on respective fields.