Restrict Anonymous: Enumeration and the Null User

by Timothy M. Mullen Sept. 1, 2017 via Symantec

If you are an NT administrator, or if you provide security policies and audits for clients, then you know all about the RestrictAnonymous value in the LSA key. If not, you need to educate yourself about this setting - not so much because of what it does, but more importantly, what it doesn't do.

https://www.symantec.com/connect/articles/restrict-anonymous-enumeration-and-null-user