Packet Capture in Cisco IOS
From Teknologisk videncenter
!<notice>An ACL must be defined to match interesting traffic only:</notice>
ip access-list extended Monitored-Host
permit ip 10.0.0.0 0.0.0.255 host 10.1.1.1
!<notice>A buffer must be defined and bounded to the previos defined ACL:</notice>
monitor capture buffer BUFFER size 512 max-size 256 circular
monitor capture buffer BUFFER filter access-list Monitored-Host
!<notice>The next step requires to define which interfaces must be monitoed and where store data:</notice>
monitor capture point ip cef CAPTURE FastEthernet0/0 both
monitor capture point associate CAPTURE BUFFER
!<notice>Finally the capture must be started and stopped when not needed anymore:</notice>
monitor capture point start CAPTURE
monitor capture point stop CAPTURE
!<notice>At this point the buffer can be exported to an external system:</notice>
monitor capture buffer BUFFER export ftp://ftp.example.com/CAPTURER.pcap