Here is an example configuration

 

monitor capture buffer pktrace1 size 256 max-size 128 circular
monitor capture point ip process-switched ipsfa0/0 both
monitor capture point associate ipsfa0/0 pktrace1
monitor capture point start ipsfa0/0

 

To look at the packet capture on the router issue the command

 

Show monitor capture buffer pktrace1 dump

 

Regards,

 

Tyson Scott - CCIE #13513 R&S and Security

Technical Instructor - IPexpert, Inc.


Telephone: +1.810.326.1444 
Cell: +1.248.504.7309
Fax: +1.810.454.0130
Mailto:   <mailto:[email protected]> [email protected]

 

Join our free online support and peer group communities:
<http://www.IPexpert.com/communities> http://www.IPexpert.com/communities

 

IPexpert - The Global Leader in Self-Study, Classroom-Based, Video On Demand
and Audio Certification Training Tools for the Cisco CCIE R&S Lab, CCIE
Security Lab, CCIE Service Provider Lab , CCIE Voice Lab and CCIE Storage
Lab Certifications.

 

From: [email protected]
[mailto:[email protected]] On Behalf Of Shawn H
Mesiatowsky
Sent: Thursday, June 11, 2009 12:25 PM
To: [email protected]
Subject: [OSL | CCIE_Security] Packet capture on Router

 

Is there a way to view a packet capture that was performed on a router using
the ip traffic export command?

The only way I have been able to view the trace is by uploading to a tftp
server and viewing in wireshark. If I use the following commands:

 

traffic-export interface fa0/1 copy flash:test.pcap

more test.pcap

 

I can see the contents of the pcap file, but it is a binary file, so I just
see the hex code for the file.

Is there a command to export captured data into a text format?

 

Will I be able to copy to a tftp server and view with wireshark in the
actual lab?

Is there a computer in the lab hooked up to the 3560 to perform a span in
the lab and capture with wireshark?

 

I love the capture functionality on the firewalls, as you can view the
contents of the capture right on the firewall itself.

I guess you can also use a debug ip packet ACL command in the lab, or use
net flow or ip accounting for troubleshooting, but nothing beats a packet
capture!

 

Maybe my strategy is wrong as well. In the real world, I use captures to
verify that packets are getting to where they are supposed to go. This is
always my second step (first being to look at logs, especially on firewalls
for denies). Should a train myself to rely less on captures?

 

Thanks for any advice!

Reply via email to