Wireshark-users: Re: [Wireshark-users] I see no captured packets at all

From: Gerald Combs <gerald@xxxxxxxxxxxxx>
Date: Fri, 29 Dec 2006 08:45:16 -0800
...or you could just buy one of these:

    http://www.cacetech.com/products/airpcap.htm

(Apologies for the shameless plug.)

Small, James wrote:
> Cor,
> 
> Unfortunately, many wireless cards in Windows do not allow you to do
> network captures.  I use to have a link to a web site that explained it
> all and had a list of Wireless NICs/Chipsets and which ones worked or
> didn't work for network captures but now I can't find it.
> 
> However, many times you can get around this by bridging if you're using
> XP.  Basically, you need to add the Microsoft Bridge and add your
> wireless adapter to it.  You then choose the Microsoft MAC Bridge
> Virtual NIC as the capture source instead of the Wireless card.  This
> works in the majority of cases - I use it myself.
> 
> If I remember correctly, in the Network Control Panel, I believe you
> select two adapters and then select bridge.  This creates a Microsoft
> Virtual Bridge with the two adapters as members of the bridge.  After
> the bridge is created, you can remove everything except your wireless
> card and try capturing as described above (just go into the bridge
> properties).
> 
> When you create the bridge, it acts just like a simple network bridge
> including emitting 802.1d spanning tree BPDUs.  Be warned, many switches
> (especially corporate ones) are configured to basically shutdown if they
> detect spanning tree BPDUs.  Usually if you're just bridging your
> wireless card this doesn't create problems.  However, I have run into
> some instances where the wireless network is seamlessly bridged to a
> wired switch and when the switch detects spanning tree BPDUs, it
> disables the switch port that the access point is on.  This is rare but
> possible so be warned!
> 
> Also, sometimes my wireless connection can be a little flakey and if I
> remove the bridge the problems go away.  That said, I usually always run
> in bridged mode so I can do captures and for the most part it works
> well.
> 
> Let me know if you have trouble setting up the bridging,
>   --Jim
> 
> 
>> -----Original Message-----
>>>> I installed Wireshark (Version 0.99.4 (SVN Rev 19757)) on my laptop
>>>> (Acer Aspire 6510 with a build in Intel PRO/Wireless 3945ABG
> network
>>>> card), running Windows XP sp2.
>>>> My LAN has an Asus WL500g router and  a 3COM switch for the wired
>>>> desktops attached to it.
>>>>
>>>> When I start capturing on the laptop, the name of my networkcard is
>>>> mentioned in the top of the capture window all right, but no
> captured
>>>> packets are shown, even if I wait for 10 minutes.
>>>>
>>>> I also uninstalled and re-installed WinPcap (version 3.1)
>>>>
>>>> What am I doing wrong? Is this network card the evil part?
>>>> On one of the wired desktops, it works fine.
> 
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