Sniffer Capture
Sometimes you might find that the syslog, after running the debug commands, might not give very conclusive results because other network-related issues could be affecting the packet flow. In this rare circumstance, capturing the sniffer traces simultaneously from incoming and outgoing interface segments might help to isolate the problem (as discussed earlier, the capture command can be used if the packets are reaching to the FWSM, but if the packets are getting dropped in another part of the network, then capture on the FWSM is ineffective). A very popular and freely downloadable sniffer software is Ethereal (www.ethereal.com)