A Google Nest speaker was winning the STP root bridge election on my network and knocking out DNS every 45 seconds. Took five separate tools to find it.I started NetSentinel one Sunday afternoon out of frustration. Thought I would be done the same evening. But I was off by about 2 months. Every time I hit a problem that lived in yet another tool, I just added it.Available on Windows (MS Store), macOS and Linux.Testers with different HW are welcome.