Re: AD authentication failure - RADIUS Windows 2012R2 setup

1. Select “Vendor Specific” under the RADIUS Attributes
2.Click Add, change the Vendor dropdown to “Custom” and click “Vendor-Specific” from the attributes 


1.Click “Add”, then “Add” on the “Attribute Information” dialog
2.Select “Enter Vendor Code” from the “Specify network access server vendor” section and enter the Juniper vendor code “2636”
3.Select “Yes. It conforms” to specify that the attribute conforms to the RADIUS RFC 

1.Click “Configure Attribute” and set the “Vendor-assigned attribute number” to “1”, which represents “Juniper-Local-User-Name”
2.Set the “Attribute format” to “String”
3.Set the “Attribute value” to “SU”. This is the local username passed to JunOS

Blogs that you are specifying are correct. Did you create the "Juniper-Local-User-Name" attribute for accounts in RADIUS like describe above?