Systems with an integrated Dell Remote Access Control (iDRAC) have a default user name and password, but you can also configure them with a secure password.

Default iDRAC login
In the iDRAC's default configuration, the login credentials are as follows:

• Username: root
• Password: calvin

Secure Password
For iDRAC9, a new feature called secure password is available during the purchase configuration.

• If you have opted for secure default access to iDRAC, the iDRAC secure password is available on the back of the system information tag (Service Tag) under "iDRAC Default Password."
• If you have not opted for secure default access to iDRAC, then the default password should be blank. In this case, the default username and password (root/calvin) apply.

For more information please refer KB article https://www.dell.com/support/kbdoc/en-us/000133536/dell-poweredge-what-is-the-default-username-and-password-for-idrac