Wireshark-users: Re: [Wireshark-users] promiscuous mode on a wireless card with a router as the access point

From: Stephen Fisher <stephentfisher@xxxxxxxxx>
Date: Mon, 11 Jun 2007 00:08:08 -0700

On Mon, Jun 11, 2007 at 12:19:41AM -0500, Terra Frost wrote:

> The Linksys WRT54G - the access point I'm using - has a built-in 
> switch, however, I'm not sure if this built-in switch is for wired 
> networks, only, or if it's for wireless networks, as well.  If it's 
> for wireless networks, then that'd probably explain why I can't enter 
> into promiscuous mode, however, what would let me enter into 
> promiscuous mode for wireless networks, then?

The ability to use promiscuous mode on a wireless LAN interface depends 
on the WLAN interface/drivers/operating system you're running and not 
the access point.  For example, my work laptop can do promiscuous under 
Linux but not under Windows.

> Linksys has a stand-alone access point (WAP54G), however, the page on 
> Linksys' website that discusses it doesn't mention anything about a 
> hub or a switch.  Does that mean that wireless access points don't 
> even use hubs / switches?

Wireless APs may have a hub or switch built in for the wired side of it 
or they may just have one wired connection.  In either case, the 
wireless and wired sides are typically bridged together (a bridge is 
just a 2 port switch).  The wireless side acts like a hub where all 
machines have to check if another station is currently using the 
wireless medium before they can transmit.


Steve