Show HN: Z-nettool – a cross-platform network troubleshooting CLI

I work at an MSP, and we often deal with poorly labelled cables and limited documentation. A common question during troubleshooting is: which switch and port is this computer connected to? Is the link negotiating at Gigabit, or has it fallen back to Fast Ethernet (100 Mbps) or even 10 Mbps due to a bad cable or port?

To make basic network troubleshooting faster, I built a small cross-platform CLI tool that bundles common checks in one place. It supports:

- LLDP discovery (useful when switch ports aren’t labelled)

- DHCP checks (including detecting multiple replies, e.g. rogue DHCP servers)

- Ping, DNS, and a basic connectivity test

The goal is to help techs remote or onsite to troubleshoot faster using a single, portable tool that works across platforms.

Built mostly for our own use, but I’ve found it handy enough to share. Feedback welcome.