Originally posted by: jcruz

Our admins for the domain controller have disabled NTLMv1 support due to a security issue.  After doing this our Samba shares were no longer accessible.  Seeing errors in the log:  "NT_STATUS_NO_SUCH_USER" and "failed to find server for "CANLAB" domain".
Tried adding the following:
ntlm auth = no
client ntlmv2 auth = yes

Originally posted by: AyappanP

From Samba 4.5 onwards , by default NTLMv1 auth is disabled.

https://www.samba.org/samba/history/samba-4.5.0.html

What is the version of Samba you are using ? 

Originally posted by: jcruz

We are running 4.6.16.

Originally posted by: AyappanP

You need to see the Samba logs to see whether the clients try to use the NTLMv1 authentication. 

Originally posted by: jcruz

this is on a test aix samba server and i'm trying to access the share from a windows 10 machine and in the log i see something like this:

[2019/12/11 13:52:16.133171,  5, pid=4128952] ../auth/ntlmssp/ntlmssp_sign.c:633(ntlmssp_sign_reset)
  NTLMSSP Sign/Seal - using NTLM1
[2019/12/11 13:52:16.161833,  3, pid=4128952] ../source3/libsmb/cliconnect.c:1675(cli_session_setup_creds_done_spnego)
  SPNEGO login failed: The request is not supported.

this occurs even with:
ntlm auth = no or yes
client ntlmv2 auth = yes

Originally posted by: AyappanP

I think you need to check the windows 10 machine whether it still uses NTLMv1 for authentication.