Usually windows clients supporting smb2 protocol do 2-step protocol negotiation, sending SMB1 negotiate with SMB2 as one of the dialect, then if server supports SMB2, client send SMB2 negotiate with the list of SMB2 dialects and server choses SMB2 dialect. In some cases Windows 7 begins SMB session with 1-step SMB protocol negotiation, starting with SMB2 negotiate. E.g. it caches knowledge that server supports SMB2. If SMB2 is disabled on the server for some reason (but not SMB1), windows 7 doesn't fall back to SMB1, so shares become inaccessible although it's still possible over SMB1, which could be a problem. Usually it could be solved by rebooting the client, but it's really necessary to find solution to this without a user actions. Is it possible to configure win7 in such way that it will always sent SMB1 negotiate allowing server to chose SMB1 or SMB2 protocol? Thanks.

1. I have never heard about the reverse procedure, namely the SMB first and SMB 2 in second attempt. Normally the SMB is lowered for incompatible clients that are present on network with commands: sc config lanmanworkstation depend= bowser/mrxsmb10/nsi sc config mrxsmb20 start= disabled 2. I am pretty sure, that there is another mechanism that prevents Windows 7 from successful set on SMB 2 use. Try to play with NIC parameters (autotuning, package size,...) Regards Milpos

SMB2 spec says (Product behavior): <93> Section 3.2.4.2.2: The Windows-based client will initiate a multi-protocol negotiation unless it has previously negotiated with this server and determined that it supports the SMB 2 Protocol. In the latter case, it will initiate an SMB2-only negotiate. So I'm interested to configure it to always send multiprotocol negotiate instead of saving knowledge about SMB2.

Unfortunately disabling SMB2 on the client is not an option. Win7 could negotiate SMB1 if it sends multiprotocol negotiate request. All I want is to disable SMB2-only negotiate somehow. Thanks, anyway.

Hi , Win7 will not automatically switch SMB2 to SMB1. You may try to disable SMB2: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters If there is no REG_DWORD value named Smb2, you will need to create it. This value does not exist by default. Once the value is created, set the value to 0 to disable SMB2 or 1 to enable SMB2. The blog for your reference: http://blogs.technet.com/b/askperf/archive/2008/05/30/two-minute-drill-overview-of-smb-2-0.aspxTracy Cai TechNet Community Support