Network Diagnostics
The Network Diagnostics package (FreeSense-pkg-Diagnostics) adds a Network Tools page that
runs a small, fixed set of diagnostic commands from the WebUI: an MTR path report, an Nmap top-ports
scan, an iperf3 throughput test, and an ARP probe. In FreeSense 1.1.0 the package is version 1.0.0
and installs mtr-nox11 0.96, nmap 7.991, iperf3 3.22 and arping 2.25 (versions as listed in
the 1.1 package repository).
Use it when the built-in tools under Diagnostics (Ping, Traceroute, DNS Lookup, Test Port, Packet Capture) are not enough: to see loss per hop, to check which common ports a host answers on, to measure throughput to an iperf3 server, or to check that a host answers ARP on a local segment. Each tool runs with fixed options; the page does not accept free-form command lines.
Install
Section titled “Install”- Open System → Package Manager → Available Packages.
- Find Network Diagnostics (package
FreeSense-pkg-Diagnostics) and select Install.
Stable packages are published for amd64 and, starting with 1.1.1, arm64.
Where to find it
Section titled “Where to find it”Diagnostics → Network Tools, in the tools group of the Diagnostics menu next to Ping, Traceroute and Test Port.
Access is controlled by the WebCfg - Diagnostics: Network Tools privilege. Give it only to administrators who are allowed to scan and load the network.
First-time setup
Section titled “First-time setup”There is nothing to configure. To run a test:
- Open Diagnostics → Network Tools.
- Choose a Tool.
- Enter the Target: an IP address or a DNS host name.
- For iperf3, set iperf3 port if the server does not use 5201. For the ARP probe, enter the ARP interface.
- Select Run and wait. The page shows the output and the exit code when the command finishes.
Settings reference
Section titled “Settings reference”Form fields
Section titled “Form fields”| Field | What it does | Default |
|---|---|---|
| Tool | Route and loss (MTR), Top ports (Nmap), Throughput client (iperf3) or Local ARP probe. | Route and loss (MTR) |
| Target | IPv4 or IPv6 address, or a DNS host name. Anything else is refused. | Empty (required) |
| iperf3 port | Port of the iperf3 server, 1 to 65535. Used only by iperf3. | 5201 |
| ARP interface | Operating system interface name, for example em0, igc1 or vtnet0 (not the FreeSense name such as LAN). Required for the ARP probe. |
Empty |
What each tool runs
Section titled “What each tool runs”| Tool | Command | Notes |
|---|---|---|
| Route and loss (MTR) | mtr --report --report-cycles 5 -- <target> |
Five probes per hop, then a report of loss and latency per hop. |
| Top ports (Nmap) | nmap -Pn --top-ports 100 -- <target> |
Scans the 100 most common TCP ports and skips host discovery. |
| Throughput client (iperf3) | iperf3 --client <target> --port <port> --time 5 |
A 5-second test from the firewall to an iperf3 server. |
| Local ARP probe | arping -c 5 -i <interface> -- <target> |
Five ARP requests on one local segment. |
Output is limited to the first 2,000 lines.
Firewall rules and interfaces
Section titled “Firewall rules and interfaces”- All tests start from the firewall itself, so they use the firewall’s routing table and source address selection. Outbound traffic from the firewall is normally allowed.
- iperf3 runs only as a client. The target must run an iperf3 server (
iperf3 -s) and accept the port you chose. To test through the firewall instead of from it, run iperf3 on hosts on both sides. - The ARP probe works only for targets on a segment directly attached to the chosen interface.
- Nmap scans can trigger intrusion detection, rate limits, or blocks on the target or on upstream networks. Scan only systems you are authorised to test.
Service, logs, and status
Section titled “Service, logs, and status”The package runs no service and writes no log of its own. Each run’s output is shown on the page only and is not stored. Copy anything you need to keep as evidence.
Upgrade, backup, and removal
Section titled “Upgrade, backup, and removal”The package stores nothing in config.xml. Removing it removes the Network Tools page and the
privilege. The tool packages it pulled in (mtr-nox11, nmap, iperf3, arping) may stay
installed as dependencies until pkg removes unused packages.
Troubleshooting
Section titled “Troubleshooting”| Symptom | What to check |
|---|---|
| “Enter a valid IP address or DNS hostname.” | The target contains spaces, a URL, a port, or other characters. Enter only the address or name. |
| “Select or enter a valid interface name for ARP probing.” | Enter the OS interface name (see Interfaces → Assignments), not the FreeSense description. |
| iperf3 exits with an error at once | No iperf3 server is listening on the target and port, or a firewall on the way blocks it. |
| MTR shows loss on middle hops only | Many routers rate-limit replies to probes. Loss that does not continue to the last hop is usually not real loss. |
| The page takes a long time or times out | Nmap against a filtered host can be slow. Try a closer target or use the built-in Test Port for a single port. |
| Exit code is not 0 | The tool reported an error; read the output on the page. |
For the built-in tools and a general troubleshooting method, see Diagnostics and troubleshooting.