I am a complete newbie when it comes to packet sniffers. I installed
Ethereal on one of our WinXP PCs and have been trying to figure out how
it works. The problem is, the only traffic I seem to be picking up is
the packets coming from the PC that Ethereal is installed on.

Have I configured it wrong, or is it because of where this PC is on our
network? Our network is set up like this:

cable modem
|
WiFi/wired router
/|\
PC#1, PC#2, PC#3, etc.

and I have Ethereal installed on PC#1.

How do I get Ethereal to be able to pick up packets sent to/from PC#2,
PC#3, etc.? Does it make a difference that some PCs are wired to the
LAN and others are using WiFi?

Thanks in advance for any help. I have a feeling the answer is probably
obvious to everyone but me.