• Tony Fortunato

Old School vs New Tool - CDP Discovery

In this video, I compare how long it takes the NetAlly LinkRunner G2 and a Windows laptop running Wireshark, to determine what switch and port it is connected to. In my opinion, this is the most common task that most IT professionals perform.

I too have been in that scenario where I'm tracing a cable in someone's office and it goes behind the desk or partition. If you are lucky, you can pull the desk aside, slide your phone behind the desk to get a photo of the cable label. In some cases, the label is missing. Would you trust the label in the first place?

Then you proceed to look for the floor map and guess what the cable identifier is, look for some sort of cable documentation, or maybe someone put a cable identification label on the switch port. But is the documentation or switch port description kept current?

Alternatively, you can get the MAC address of the client's computer and check the local switches to see which port it is associated with. Tough for me, as an external consultant in most environments, I typically don’t have management access. Even if I did, going to a switch CLI (“show mac address-table dynamic” or similar) or web management interface… You can easily spend 30 minutes trying to figure this out.

Lastly, if you have SNMP enabled and access to the SNMP read-only string, and the proper SNMP query tool, you can try to figure it out that way.

Sometimes it's hard to justify the cost of a tool but exercises like this helps and I would encourage you to do the same. This is also valuable when comparing tools. You can compare how long it takes to do the most common task, or the number of clicks, etc.

Update... It was suggested that I add another test. Same procedure but with the LinkRunner G2 and Laptop already powered on.

Here are the results:


Average Time (seconds)

LinkRunner G2


Laptop with Wireshark


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