I was getting the following messages in my samba logs when I would try to access a samba 3.0.33 share on CentOS 5.4 from a Windows 7 Enterprise client:

[2010/03/04 14:07:12, 0] lib/util_sock.c:read_data(534)
read_data: read failure for 4 bytes to client 172.18.31.155. Error = Connection reset by peer

I tried adding the following to my /etc/samba/smb.conf global configuration, but it did not seem to work.

client ntlmv2 auth = yes

I got the same kind of messages.

I ended up having to change the Windows 7 local security policy by modifying the “LAN Manager authentication level”, the “Minimum session security for NTLM SSP based (including secure RPC) clients”, and the “Minimum session security for NTLM SSP based (including secure RPC) servers” policies.

I used the following procedure:

Control Panel -> System and Security -> Administrative Tools -> Local Security Policy

From the Local Security Policy, I went into “Security Options” and then looked under the “Network security” policies.

From here, I set the new policies.

Network security: LAN Manager authentication level
Send LM & NTML responses

Network security: Minimum session security for NTLM SSP based (including secure RPC) clients
Uncheck “Require 128-bit encryption.”

Network security: Minimum session security for NTLM SSP based (including secure RPC) servers
Uncheck “Require 128-bit encryption.”

I am hoping to figure out the issue with samba not accepting ntlmv2 authentication, so I can set the client policies back to the default.