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Subject: CIPE Virtual NIC
From: #PRAKASH SANDEEP# <V431194,AT,ntu,DOT,edu,DOT,sg>
Date: Thu, 10 May 2001 04:30:43 +0200


Hope this helps to sort out the problem I metioned earlier.

I can only read from the tap device the first time it is installed. After
that any more attempts to read from it are met by "Overlapped I/O in
progress" error. This happens even if I ping the gateway I have set for my
laptop (see the email below for reference).

Thanks and regards,


I would really appreciate any help on the problem I have.

I have a win2k laptop witthout a physical network adapter. I am using the
CIPE virtual adapter to obtain the ethrnet frames generated as a reult of
TCP/IP communication. I will be transferring these frames via Bluetooth.

I have a few problems with the CipeTapIO program. I have modified it a bit.
I can get a valid handle for the virtual NIC. However, when I try to perform
a ReadFile operation on the NIC I get "Overlapped I/O in progress" Error.
This means that no data has been received on this adapter. However, this is
the only adapter I have set up on my laptop and I have given it a fixed IP.
I have also fixed the gateway. 

Now, when I try to ping the gateway ARP frames should be generated (ARP
table is empty and this is the first IP communication on starting up the
laptop) by the TCP/IP stack right? I should be able to read these on
ReadFile right? I wait for an event on the m_Overlapped structure used in
ReadFile. I still do not get any packets.

When I tried my code the first time it did give me some packets. But, now it
does not. I have the problem mentioned above.

As I said earlier I get a valid handle for the device and pass it to the
ReadFile for overlapped I/O.

Also, sometimes I am unable to get a valid handle for the driver. I can get
a valid handle again once I restart the laptop.

Any help on this would be really appreciated.


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