users with XP can map drives but Win7 cannot

the digitally sign communications settings are the same for the XP box as the Win7 box, and they both have send unencrypted password to 3rd party SMB disabled

on the win7 box

Local Policy | security options | Microsoft network client

digitally sign communications if server agrees is enabled

digitally sign communications always is disabled

send unencrypted passwords to 3rd party SMB servers is disabled.

Do you mean that this last setting must be enabled, or are you referring to some other setting?

Look into smb signing option

what version of File OE is running on your VNX ?

could they provide you with output from this command:

[nasadmin@vnx~]$ server_param server_2 -facility cifs -list | grep smbsigning

smbsigning                          cifs          1          1

as you can see on my VNX it's set to 1,  Win7 clients connect ok.

I do know that it was an acute change one day last week during the day.  Was working fine for months.  Appears that some setting was changed on the VNX box

Asking IT now.  I run the departmental side for a large group of users-- no direct access to the server side.  Only direct access to the clients

thanks for this further info.  I've passed the request to IT.

Why don’t you just use the CIFS server name instead of the IP?

I think depending on whether you use IP or Netbios name or DNS name different protocol versions (SMB1, SMB2) and authentication methods are used (NTLM/Kerberos)

Also Windows7 supports up to SMB 2.1 whereas XP only support SMB1

Besides other security settings that are different like SMB signing as dynamox mentioned

I am using the FQDN of the server.  How does this differ from the CIFS name.

anything new got pushed out using AD GPOs ?

I tried turning off SMB2 in windows 7 (while leaving SMB1 on) but that broke all my existing SMB shares.  The local security networking settings on all these computers are the same.  In addition, the change happened to 20 computers all at once at a single point in time 1 day ago.  Windows 7 and server 2008 computers lost SMB access to the VNX box, while XP machines retained access.  Others on a different part of the network, did not lose access.

Thank you both for your input.  There was a change to our very large network that required the addition of a new DNS and WINS Server in the network setup for Windows 7 and Server 2008 R2.  I can't explain why XP boxes work just fine without these new settings, but it must somehow relate to SMB1 vs SMB2.

Might be that the XP boxes find the server names via NetBIOS broadcast