ISR4k: IOS-XE Embedded Packet Capture

A few years ago I posted an article about the embedded packet capture tool (EPC) in Cisco devices running IOS. This quick article is an update of the previous one with the IOS-XE flavor.

I run this test on an ISR4351 with IOS XE 3.16.01a.S, IOSD 15.5(3)S1a.

First, you need to define the interface where the capture will occur and the traffic to be captured

ISR4351#monitor capture CAP interface tun 10 both
ISR4351#monitor capture CAP match ?
  any   all packets
  ipv4  IPv4 packets only
  ipv6  IPv6 packets only
  mac   MAC filter configuration
ISR4351#monitor capture CAP match ipv4 protocol tcp host any

Then start the capture:

ISR4351#monitor capture CAP start

You can prior to that, alter the buffer size for the capture. It can be done with the “monitor capture CAP buffer size XXXX” command where the XXX is in megabytes.

Once done, capture need to be stopped before export

ISR4351#monitor capture CAP stop

Then the buffered data can be exported to local or remote location as a PCAP file.

ISR4351#monitor capture CAP export ?
  bootflash:  Location of the file
  flash:      Location of the file
  ftp:        Location of the file
  harddisk:   Location of the file
  http:       Location of the file
  https:      Location of the file
  pram:       Location of the file
  rcp:        Location of the file
  scp:        Location of the file
  tftp:       Location of the file

ISR4351#monitor capture CAP export flash:CAP1.pcap
Exported Successfully

Then delete the capture point:

ISR4351#no monitor capture CAP

Hope it helps,

Link to Cisco documentation: