nnamp question

[gahn]

Hi:

I have a machine with four interfaces connecting four
different networks. I am learning to use nmap and
trying to force the nmap working only one interface.
As nmap man page states, I use -e option and it would
not work:

nmap -e fx0 -v -sP 192.168.128.0/23

Starting Nmap 3.95 ( http://www.insecure.org/nmap/ )
at 2006-02-04 14:04 CST
getinterfaces: Failed to open ethernet interface (el0)
QUITTING!

What did I do wrong?

Thanks

__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com