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Monitoring the IPs in Bandwidth Usage



So I have a LAN that consists of several 3560 switches (which also acts as the gateway). I am trying to monitor the top talkers. I guess I can do this via port mirroring. So I mirror the port that goes to internet. My questions are,

1. What should be the destination for this port mirroring. If I forward this to the machine running PRTG, doesn't the PRTG system become unavailable. As the Cisco mirroring will make the IP of the PRTG server interface unreachable.

2. Can I have forward the mirrored traffic from the switch to a different interface of the server? Can PRTG read the traffic of the other NICs of the same server?

3. Last, once we get the traffic to the PRTG server, what needs to be done?


cisco packet-sniffer prtg

Created on Mar 8, 2012 9:18:49 PM

1 Reply




use a second nic in the PRTG server and connect the mirroring port to it.

Then create a packet sniffing sensor on your probe device, selecting the NIC the mirror port is connected to.

If you need to do this with several switches in different locations, you could use remote probes to connect the mirror ports to.


Created on Mar 9, 2012 6:38:07 AM by  Aurelio Lombardi [Paessler Support]

Disclaimer: The information in the Paessler Knowledge Base comes without warranty of any kind. Use at your own risk. Before applying any instructions please exercise proper system administrator housekeeping. You must make sure that a proper backup of all your data is available.