smbclient, Workgroup, Kerberos and NT_STATUS_NOT_SUPPORTED

Trying to list shares of a windows machine

smbclient -W WORKGROUP -U user -L //server.domain/
Password for [WORKGROUP\user]:
session setup failed: NT_STATUS_NOT_SUPPORTED

and failing?

Running with -d 10

Kinit for user@WORKGROUP to access server.domain failed: Cannot find KDC for requested realm
...
Failed to start GENSEC client mech gse_krb5: NT_STATUS_INTERNAL_ERROR
...
Starting GENSEC submechanism ntlmssp

and seeing it falling back to NTLM?

Using the REALM instead of WORKGROUP helped:

smbclient -W REALM -U user -L //server.domain/