Learn about a free tool for finding out what devices are connected to the ports of a switch.
One of the most critical and time-consuming tasks network technicians perform is determining what port a host is connected to; having to perform this work remotely makes it even more challenging.
I’ve worked with many applications that perform a switch port inventory. Some are too expensive, and many are included as part of an overall network management application. Buying an entire platform for one application makes no sense. Moreover, some of the hardware requirements are onerous.
So I was pleasantly surprised when I came across a switch port discovery tool for Windows called Switch Miner on Sourceforge.net. Switch Miner primarily uses SNMP for discovery, but can also use ping depending on which options you choose. Two versions of Switch Miner are available: Switch Miner GUI, which performs an inventory with a GUI interface, and Switch Miner Console, which uses the command line. In the video below I demonstrate the tool and run through some of its features.
Switch Miner is fast, reliable, and runs just fine on any of my Windows systems. For example, I ran a port inventory in 10 seconds on my Cisco 3750 switch using the Switch Miner GUI tool. When I added my router, a ping sweep and the consolidate option, discovery took just two minutes, with the ping sweep taking the longest using default settings.
The Switch Miner GUI tool has a very simple interface with no annoying ads. It displays port descriptions, speeds, duplex, VLAN, what MAC address is on that port with the manufacture's (OUI) identifier, as well as common error counters. Just remember that access point and trunk ports will have more than one address device associated with them.
Switch Miner Console captures the same information as the GUI version and creates an Excel spreadsheet with the results.
A port inventory is essential for all areas of networking: design, implementation, and support. When working on replacing network equipment, it's imperative to get an accurate inventory of port connections. In some cases, you can disconnect empty ports or order equipment with more ports if you are running low. In other situations you might want to move some connections around so port mapping is helpful.
During implementation, I like to have a print out of what is connected. A print out is important since the server and network may not be available during your installation. And for support, having the correct port number is critical when port mirroring or using a tap.