How to use Wireshark to monitor the inside interface of a cisco ASA or PIX?

Posted on 2011-03-23
Last Modified: 2012-05-11
I've used wireshark to capture network data from a computer/server, but I've never used it to capture traffic on a firewall or router.  Is it possible to use wireshark to capture network traffic on the inside interface of my firewall or router?  Thanks.
Question by:denver218
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Expert Comment

ID: 35200662

If you have managed switch you may try to make port mirroring on it. Try to mirror your CISCO port and grab traffic from there. By the way, what model do you have? What switch they are connected to?

Author Comment

ID: 35201358
I actually have two separate networks on would like to gather stats on.  One has a cisco ASA5510, the outside interface of the ASA Connects to a cisco 3640 Router, and the inside interface of the ASA connects to a cisco 3550 switch.  The second network has a Pix 506E, the outside interface goes to a cisco 2621 Router, and the inside interface goes to a cisco 2950 switch.  Can you show me an example of port mirroring?  Thanks.

Expert Comment

by:Jerry Mills
ID: 35201598
This will tell you all your options:

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Accepted Solution

laughelemental earned 500 total points
ID: 35204605
As for your inside PIX506E-have a look at
And you'll have to connect a computer with wireshark to SPANned port

Also you may try to get extednded cisco statistics via SYSLOG (install kiwi syslogd on your  windows PC) and enable DEBUG level of detalization on your device.

Author Comment

ID: 35206250
Thanks.  Ok, so let me get this straight.  This inside interface of the Pix connects to a cisco 3550 switch.  All ports on this switch are in VLAN 1.  So would I be correct in adding the below configurations to my switch:  Would doing to capture traffic from all of VLAN1?  Thanks.

c3550(config)#monitor session 1 source vlan1
c3550(config)#monitor session 1 destination interface fastethernet 0/48 (I would connect my laptop with wireshark to this port.)


Author Closing Comment

ID: 35257130

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