JACKPROBE

Manual

Every control, and what it does

One button, one light, one web console. This page is the whole instrument. The timings and figures here are taken from the firmware and checked against it automatically, so the page cannot drift away from the device.

The button

Four gestures

The tester has one button. A hold is recognised when you let go, not while you are holding, and the light changes colour as you pass each threshold so you can see which gesture you are about to commit before you commit it.

PRESS
Run the test again
A single press. Runs a fresh AutoTest and shows the verdict on the light.
PRESS ×2
Save a report
Two presses inside 350 ms. Runs a fresh test and writes an HTML report, then flashes white twice to say it was written, or red three times if it was not. The report is saved without a label; to name it, use the web console instead, or rename it there afterwards.
HOLD 1.5 s
Turn internet sharing on or off
Hold until the light turns amber, then let go. The setting is stored and the tester restarts. See the warning further down this page before using it on a network you do not own.
HOLD 5 s
Reopen the hotspot
Hold until the light turns white, then let go. Clears the hotspot password and leaves the hotspot open. This is the way back in when the key has been forgotten, and it needs no cable and no computer: anyone holding the button for five seconds is standing at the device, which is the same trust boundary the key was protecting.

Presses shorter than 40 ms are ignored, which is the contact bouncing rather than a person. Because a single press has to wait 350 ms to find out whether a second one is coming, every single press carries that much delay before it acts.

The light

Every colour it shows

Test results

Green
PASS. Link, addressing and internet reachability are all healthy.
Amber
WARN. On the network, but something is off.
Red
FAIL. This drop is not usable.
Blue
A test is running.

Waiting, and gestures

Dim green
Cable is in and linked, waiting for the next test.
Dim red
No cable, or nothing at the other end of it.
Amber, while held
You have reached the internet sharing gesture. Let go to commit it.
White, while held
You have reached the reopen-the-hotspot gesture. Let go to commit it.
White, two flashes
A report was written. Three red flashes mean it was not.

The hold colours are deliberately amber and white rather than green or red, and the save flashes are deliberately unlike any verdict colour. A light that reports the storage must never be mistakable for a light that reports the network.

The web console

Getting to it

The tester runs its own WiFi access point. Join it from a phone or a laptop and open the address below. Nothing is installed, and no internet connection is involved: you are talking to the instrument directly.

The hotspot is open when the device leaves the factory. You can set a password from the menu, and if it is forgotten, the five second button hold clears it.

Connection

Network nameJACKPROBE
Addresshttp://172.16.0.1
Or by namejackprobe.local
Passwordopen by default
Key length8 to 63 characters
Serial consoleUSB-C, 115200 baud

The menu

Every item, and what it changes

Saved reports
The list of reports held on the tester, newest first. From here you open one, rename it, delete it, download one, download all of them as a ZIP, or delete every one of them. Renaming changes the label, never the date.
Internet sharing
Shares the tested drop's internet connection with the phone joined to the hotspot. Off unless you turn it on. Turning it on restarts the tester, and it asks first.
Time zone
Which zone report timestamps are written in. The choice is stored and survives a restart. Daylight saving is handled by the zone rather than by a fixed hour offset, so a report taken in March and one taken in November are both right.
Hotspot key
Sets or clears the hotspot password. Leave it empty to keep the hotspot open. Setting a key restarts the access point, so the phone you are holding will drop off and need to rejoin.
Internet check
What the tester connects to in order to prove a drop reaches the internet, as an address and a port. It completes a TLS handshake there, which a captive portal cannot answer. Change it if your network blocks the default of 1.1.1.1:443, and prefer an address over a name: this check exists to tell a broken resolver from a broken uplink, and it cannot do that if reaching it needs the resolver.
Notifications
A webhook address. Each time a report is saved the tester posts a summary there. See below for exactly what it sends and what it does not.
About this unit
Serial number, firmware version, time zone, and how much report storage is left.

Reports

What is saved, and how to get it out

A saved report is one HTML file. Everything it needs is inside it: no images to fetch, no stylesheet to find, nothing that stops working when it is mailed to somebody else. It opens in any browser and prints cleanly.

It carries the verdict, every reading, the label and the notes you typed, the switch and port where those were advertised, the unit's own serial, and both local time and UTC.

Reports are held in the tester's internal flash. There is no memory card. To get them out, use the web console: download one from the button beside a report, or all of them at once as a ZIP.

Storage

Whereinternal flash
Partition3.4 MB
Capacity394 reports
One reportabout 6 KB
Memory cardnone

Capacity was measured by filling the partition, not estimated from a file size. The console shows a slightly lower number as it counts down, because a report grows a little with a longer label and longer notes.

Notifications

The webhook, precisely

What it sends

An HTTP POST with a flat JSON body, each time a report is saved. It carries the verdict, the label and notes, the report's filename, the unit serial and MAC, local and UTC time, link state and speed, whether DHCP answered, the IP, gateway and public address, the gateway, DNS and internet results, the gateway latency, and the switch name, port and VLAN where they were advertised.

What it does not

It does not send the HTML document, only the summary. Nothing is queued and nothing is retried, so a POST that fails is lost and the console says so. It is not attempted at all on a drop with no internet, for the obvious reason.

HTTPS addresses are accepted but the certificate is not verified. This device has no certificate store and no clock until the drop has internet, so a check would be theatre rather than security.

Treat it as a convenience, not as a record. The report on the tester is the record. The webhook is a copy sent once, on a best effort, to somewhere you chose.

Listening

What the tester overhears, and what that is worth

Three things are learned by listening rather than asking: the switch, whether the port wants you to authenticate, and what else answers DHCP here. Nothing is transmitted to obtain any of them.

None of these can tell you something is absent. That is a property of listening, not a shortcoming we intend to fix, and the tester will never claim otherwise. Read the next two panels before relying on a quiet result.

802.1X

It can tell you a port asked. Never that it did not.

A switch enforcing 802.1X sends an identity request when a device appears, then a couple more, and then stops. Re-authentication is off by default on most switches. So on a port whose requests finished before you plugged in, no amount of waiting will produce one.

That is why there is no "802.1X not in use" reading. A tester that offered one would be inventing it out of a silence that proves nothing. What you get instead is what was heard, with how long it listened and how many frames went past while it did.

DHCP

It reports what answered. Not how many exist.

The useful finding is a second DHCP server: two of them handing out conflicting addresses is a real outage, and the second is usually a small router somebody plugged into a wall port. The tester names both, with the MAC address of each, which is what you need to find the port it is on.

It cannot tell you there is only one. Moving between jacks, the tester usually renews the address it already has rather than asking from scratch, so nothing prompts a second server to speak up and its silence means nothing.

Reading a quiet result

"No 802.1X seen yet. Listening 26 s, 344 frames."
Nothing was heard, and the segment was busy while we listened. The tester is working; either the port does not use 802.1X, or its requests finished before you arrived. You cannot tell which from here, and neither can the tester.
"Nothing heard at all in 26 s."
Zero frames. This is a statement about the tester, not about the network: on a live segment something always arrives. Suspect the cable or the port before you suspect the finding.
"This port asked us to authenticate, and let us on anyway."
A request was heard and an address was still handed out. Open mode, a guest VLAN, an auth-fail VLAN and MAC address bypass all look identical from outside, so the tester names all four rather than guessing. It never says a port is enforcing anything, because a port configured to ask and then let everyone through sends exactly the same frames as one that does not.
"Not checked: the tester could not listen on this jack."
The listening tap is not in place. Nothing about 802.1X or DHCP on this report means anything; treat those sections as blank rather than as negative.

Internet sharing

Read this before turning it on

It makes the tester a router. With sharing on, the device forwards traffic from the phone on its hotspot out through the tested drop. That is exactly the behaviour network access control looks for, and on a client's secured network it can get the port shut down and you escorted out of the building. It is off unless you turn it on, it asks before enabling, and the sensible default on any network you do not own is to leave it alone.

What it is genuinely useful for: your own bench, a site you own, or a situation where you need the phone online to look something up and the drop you are testing is the only connection in the room.

Time

What the timestamps are worth

The clock is set by SNTP the first time the tester reaches the internet through a drop. Your time zone choice is stored and survives a restart; the clock itself is not, so after a power cycle the time is only as good as the next successful sync.

A report saved before any sync is stamped honestly rather than plausibly: its filename says there was no clock and gives the uptime instead of inventing a date. Those reports sort to the bottom of the list, because they have no place on a timeline.

If exact times matter for the work you are doing, plug the tester into a drop with internet before you start, and keep it powered.