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Cisco SPAN/Mirroring and PRTG Packet Sniffer



Hi Guys,

I'm just new here and trying to learn to use PRTG, I have setup a lab environment which I want to test capturing traffic.

I have a cisco C3560E switch and a server with PRTG installed and running OK. On the Cisco switch I have the int0/1 going to the Firewall and configured to be the source. While the PRTG server is connected to the int0/24 of the switch and configured to be the destination.

However, as soon as I configured int0/24 to be the destination PRTG loses connectivity to everything.

switch#sh run Building configuration...

Current configuration : 1862 bytes ! <SNIP> interface GigabitEthernet0/1 ! interface GigabitEthernet0/24 ! monitor session 1 source interface Gi0/1 monitor session 1 destination interface Gi0/24 end


Am I doing it correctly? I am really sorry, I know this is really dumb.

Thanks, James

packet-capture packet-sniffing prtg

Created on Dec 12, 2017 6:14:49 AM

1 Reply



Dear jvictorio,

could it be that the packet sniffer sensor gets overloaded with that configuration? Beside using a more powerful CPU, you can try to set an input filter in the packet sniffer sensor settings. This means to narrow down what will be analyzed, but also can offload the CPU.

Created on Dec 12, 2017 12:32:59 PM by  Arne Seifert [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.