Wireshark · Ethereal-users: Re: [Ethereal-users] Using Ethereal on an Intel Centrino WiFi card

[Guy Harris <gharris@xxxxxxxxx>]

Keefe Johnson wrote:
> I have a Dell Inspiron 500m with an Intel 2100 3A MiniPCI WiFi Adapter. 
> I also have a cabled ethernet connection. I can successfully capture 
> packets with Ethereal on my ethernet connection, but when I try to do 
> the same on my wifi, I get no packets. No errors either, it just sits 
> there capturing nothing. I successfully use nmap on both my wifi and 
> ethernet, so I assume that the problem isn't winpcap.

Does nmap require promiscuous mode to work?

A quick look at the source to nmap indicates that it'll use promiscuous 
mode only if the "-S" flag is used.

If you weren't running nmap in promiscuous mode, then the fact that it 
worked on your wifi interface doesn't indicate that the problem isn't 
WinPcap or the driver.

As the FAQ item Ulf referred to notes, wireless drivers on Windows often 
don't handle promiscuous mode very well.

> Maybe Ethereal can't work with Intel Centrino 2100?

Ethereal doesn't directly work with any network adapters - it works with 
libpcap/WinPcap.  libpcap doesn't directly work with network adapters 
either, it works with the OS's capture mechanism, and WinPcap's driver 
works with NDIS - i.e., none of that code knows whether it's dealing 
with a particular network adapter - so if there's a problem with a 
wireless interface that doesn't show up with other interfaces, it's 
almost certainly a driver problem.