Tired of setting up SPAN sessions? Need to do some packet analysis? Since IOS 12.4(20)T Cisco has made Embedded Packet Capture (EPC) available. EPC is a powerful troubleshooting tool that allows engineers to capture packets inside a Cisco router which can be essential in many troubleshooting scenarios.
http://routerjockey.com/2011/02/14/ios-embedded-packet-capture/
