Jeff,

Could you provide some network captures so I can further investigate the 
behavior you described?

Thanks,
Edgar

-----Original Message-----
From: Jeff Layton [mailto:[email protected]] On Behalf Of Jeff Layton
Sent: Tuesday, December 07, 2010 3:27 PM
To: Edgar Olougouna
Cc: Christopher R. Hertel; [email protected]; [email protected]; MSSolve 
Case Email
Subject: Re: [cifs-protocol] [REG: 110120160951867] Requesting clarification of 
CIFS client timeout behavior

On Tue, 7 Dec 2010 20:56:17 +0000
Edgar Olougouna <[email protected]> wrote:

> Jeff,
> 
> I have been working with the product group on this issue regarding 
> Windows-based CIFS clients' timeout behavior. Please find the answers as 
> follows. Let me know whether you need further clarifications. The product 
> group is working on fleshing out the relevant Windows behavior notes.
> 
> 1) If the server is responding to the echo requests, does the client still 
> eventually return an error to the application or does it wait indefinitely 
> for the response?
> 
> Answer:
> If the server is responding to the echo requests, the client will wait until 
> the session times out, and the client will not send any "interim" response to 
> the calling application.
> 
> 2) If it returns an error to the application, does the client send a 
> SMB_COM_NT_CANCEL to cancel the outstanding request?
> 
> Answer:
> The client will not send a CANCEL request on any outstanding request; it 
> simply tears down the connection after the session times out.
> 
> 3) If it waits indefinitely, does it send more than one echo request?   If 
> so, how frequently are they sent?
> 
> Answer:
> Echo requests are sent only when the connection has been idle for more than 
> the session timeout. The default session timeout value is 45 seconds in 
> Windows NT, and 60 seconds in Windows 2000 and onward. If there is no 
> response on the connection for another session timeout, the client will tear 
> down the connection.  If there is "any" response, it will not disconnect. The 
> same repeats again.  
> 
> 4) Do more recent versions of Windows behave similarly?
> 
> Answer:
> Yes, there is no behavior change in recent versions of Windows.
> 

Thanks Edgar...

I have to point out though that after I asked this question, I did some testing 
with a crippled samba server that never replies to write requests. With win2k8, 
trying to copy a file to such a server generally caused the client to do a 
single SMBecho while waiting for the write reply. It received the echo reply 
and then shut down the socket 30s later. The timing varied a little, but it 
pretty much always closes down the socket.

It's possible I have something configured strangely or that something else was 
forcing a reconnect, but my experience doesn't bear out what you're saying 
above. If you're interested I can set this up again and provide some captures.

--
Jeff Layton <[email protected]>

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