Is it possible to monitor (Using Wireshark) the traffic exiting a Cisco 877

Unanswered Question

Hi All

I would just like to ask if it is possible to monitor the traffic exiting a Cisco 877 router on the ADSL interface.

I have tried this by inserting a Ethernet Hub, so the ADSL cable (4 wire phone cable with Rj11 plug) connected into the uplink port on the hub. I then made two more cables using 4 wire cable with an RJ45 on one end and an RJ11 on the other.

On the RJ45 side I used the 4 center pins (3, 4, 5 & 6). One cable was straight and the second was a rollover. I connected a laptop running wireshark to another port on the hub, hoping to capture the outgoing traffic.

However using this setup, neither cable brought up the ADSL connection :(, the CD LED just continually flashed instead of going to stable green.

I am trying to trouble shoot a connectivity issue between equipment in my place of employment and another site in another country. The traffic is going over the internet, via ADSL on my side and I would like to be able to show my ISP that my Cisco 877 is sending the traffic out so they will help me troubleshoot this issue. The foks at teh remote site say thay cannot see my traffic arriving.

Any help or advise would as always eb much appreciated.

Best Regards,


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patrickvanham Thu, 07/02/2009 - 02:11
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You cannot capture ADSL traffic on an ethernet hub, the ports won't even come up. If you want to analyze traffic you could monitor the ADSL interface and send the traffic to a designated port if the 800 series ISR supports the monitor session command

pompeychimes Thu, 07/02/2009 - 07:11
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There are a few things you can do to confirm traffic is leaving your ADSL interface. Debug ip packet is one. IP Accounting is another. Embedded packet capture is yet another.


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