NetApp
Configuration > Protocols > iSCSI : Managing iSCSI : Changing the default initiator authentication method
Changing the default initiator authentication method
You can change the default authentication method, which is the authentication method that is used for any initiator that is not configured with a specific authentication method.
Steps 
1.
From the Home tab, double-click the appropriate storage system.
2.
In the navigation pane, click Configuration > Protocols > iSCSI.
3.
In the Initiator Security tab, click Edit in the Default Security area.
4.
Change the security type.
For CHAP authentication, you must provide the user name and password and confirm your password for inbound settings. For outbound settings, this is optional.
5.
Click OK.