[Samba] smbclient -L succeeded even network is down

[David Roid]

Hello list,

Accidentally I found that when network is down "smbclient -L localhost -U%"
became slow however it still succeeded after like half a minute.

This is weird because my Samba server is running inside AD,

Q1. How can smbclient authenticate without talking to AD controller? I think
in this case smbclient at least tried to (reach AD controller),  otherwise
shouldn't take it so long.
Q2. Is there anyway I can suppress the authentication against AD controller
if I'm root?

Might be trivial questions, could anyone help?

Bests
-David