In the Microsoft documentation about using Kerberos, it is stated that:
Both the server and the client computers must be members of the same Windows domain or members of trusted domains.
If this criteria fails then Windows will revert to NTLM authentication.
I understand the concept of a client computer being in a Windows domain will satisfy the criteria for sharing the Kerberos authentication but I am interested in the other part of the OR criteria, "or members of a trusted domain".
How is this membership defined? The definition here is not very clear. More specifically I would like to provide membership to a Linux based machine. Is this outside of the Microsoft's intended design when they designed the definition of a "trusted domain"?