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Subject: RE: CIPE-Win32 transfer hangs
From: Jan Olderdissen <jolderdissen,AT,ixiacom,DOT,com>
Date: Fri, 8 Mar 2002 22:46:51 +0100

This is making more and more sense. I haven't tried to log the error code as
you suggested because the machine I can do this on is not currently hooked
up to anything. However, check out the return code WSAECONNRESET from
WSARecvFrom(). The description states: "The virtual circuit was reset by the
remote side executing a hard or abortive close. The application should close
the socket as it is no longer useable. On a UPD-datagram socket this error
would indicate that a previous send operation resulted in an ICMP "Port
Unreachable" message." 

This would explain the symptoms beautifully.


-----Original Message-----
From: Damion Wilson [mailto:dwilson,AT,ibl,DOT,bm
Sent: Thursday, March 07, 2002 08:33
To: Jan Olderdissen
Cc: Juan Antonio Ruiz Zwollo; cipe-l,AT,inka,DOT,de
Subject: Re: CIPE-Win32 transfer hangs

I never see it. Ever. I just installed CIPE-Win32 on a  Win2k Fujitsu laptop

for a client who was using it to manage his network from home and it doesn't

do it. None of my test boxes have ever exhibited; either on NT4.0 or Win2K.

As a correction to my answer to Juan Antonio, the message has nothing to do 
with cipdrvr.sys. In fact it is in the asynchronous I/O to the UDP socket 
used to implement the tunnel.

IN the method CipeSocketIO::RequestAsyncReceive(), the code attempts to do 
multiple Winsock WSARecvFrom's using an Overlapped I/O structure which has
been initialized with an Event. If the WSARecvFrom succeeds in 
returning data, the data is handled synchronously. The only time that the 
call should fail is when there is no data to be read, which should only 
result in a pending read request to be satisfied later using the overlapped 
I/O; this returns the status WSA_IO_PENDING. Anything other that this value
consider an error and the socket will not be able to get data without
the socket again.

Here's the code excerpt from CipeSocketIO.cpp:
        while (m_Synchronous = (WSARecvFrom (m_Socket, &l_Desc, 1, 
&m_Buffer.length, &l_Flags, (struct sockaddr *) &m_PeerInfo, &l_PeerLen, 
&m_Overlapped, NULL) != SOCKET_ERROR))

        if (WSAGetLastError() != WSA_IO_PENDING)
            DbgPrint ("[%s] failed on pending read attempt\n", 

Jan, I can generate you a cipsrvr.exe that prints out the value of 
WSAGetLastError() so that I can see what Winsock wants. If you can do this 
without my interaction then that'll be even faster. I have heard some things

about the granularity of Events and overlapped I/O before so maybe this 
problem is a known, resolvable one.

Thanks guys,


On Thursday 07 March 2002 11:43 am, you wrote:
> "failed on pending read attempt" seems to be an ongoing issue with the
> Windows version of cipe. I get it quite often too. Another issue is that
> the service will just exit at higher throughput rates. On an older Ixia
> test chassis using a Pentium MMX 233Mhz, this happens at around 150kB/s.
> Jan
> -----Original Message-----
> From: Juan Antonio Ruiz Zwollo [mailto:J.Antonio,AT,jaruz,DOT,com
> Sent: Thursday, March 07, 2002 6:41 AM
> To: cipe-l,AT,inka,DOT,de
> Cc: sandino,AT,sandino,DOT,net
> Subject: CIPE-Win32 transfer hangs
> Hi!
> On one side, I'm using CIPE-Win32-2.0-pre10.
> On the other side, cipe-1.5.2 on Linux.
> There are various tunnels going from the Linux box to other Linux boxes.
> All work fine. But the tunnel to the Win32 box hangs every few minutes.
> I ran the Win32 CIPE as a console, and found out that each time the
> transfer hangs, the following output appears:
> [SIP] failed on pending read attempt
> It is strange that the transfer just stops and the tunnel no longer works
> but CIPE continues to run. If it would at least stop itself, I could
> restart it every time the tunnel hangs.
> What can be done? I already tried setting the Timeout value higher.
> Kind regards,
> Juan Antonio Ruiz Zwollo

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