Ethereal-users: Re: [Ethereal-users] Nee Help With Capture Filters- new to	Ethereal..Need help..
On Friday, June 20, 2003, at 12:00AM, Ka K. Lor wrote:
I doing a project on Ethereal and trying to write a manuel for it 
using my
understanding....
I download winpcap 3.0 and ethereeal  to install on my window xp.  
After
install it, if click on capture....it will pretend like it will capture
something..but nothing will be capture...I don't know how to define the
filter or initial filter to start with...
Try starting with *nothing* as the filter - leave the "Filter:" field 
blank.  If it doesn't capture any packets, adding a filter won't help - 
a filter only *reduces* the number of packets captured (it "filters 
out" some packets and discards them), it can't cause *more* packets to 
be seen than would be seen with no filter (which means "don't filter 
out *any* packets).  If you're not seeing any packets, see
	http://www.ethereal.com/faq.html#q5.1
I need help with filter, after reading the given manuel, I still don't
understand how to define filter under ethereal on window platform...
You define it the same way you define it on UNIX.  See the 
tcpdump/WinDump man page for the platform on which you're running 
Ethereal; for WinPcap 3.0, for example, see
	http://windump.polito.it/docs/manual.htm
Look for the section that begins with
	expression
		selects which packets will be dumped. If no expression is given, all 
packets on the net will be dumped. Otherwise, only packets for which 
expression is `true' will be                     dumped.