which rule dropped the packet?

[Peter A. Felvegi]

hello,

 is there a way to easily find out which fw rule caused the packet to be
dropped? the fw logs before drops, but the ips and ports are of little
help.
 if i forward a port to the lan, it works fine, can reach a local machine
from outside.  if i forward the same port to another machine on the inet,
the fw (on the machine that does the port forwarding) drops the packets.
why could that be?

                                                        thanks, p