Support / Install a probe

Install a probe

A SquidGrid probe is one lightweight container you run at a site. It measures the paths you point it at and sends readings out — nothing listens, nothing captures your traffic. Most people are done in a couple of minutes.

Before you start

A host at the site that can run a container — Docker or Podman, Linux, x86-64 or ARM.
Outbound connectivity only: HTTPS on TCP 443 to collector.squidgrid.net for enrollment and result delivery, outbound ICMP echo for reachability and latency, and outbound UDP with returned ICMP for traceroute. Most networks allow all three by default; restrictive egress policies or some container platforms may need explicit allowances.
No inbound ports and no root. The probe runs unprivileged and listens for nothing.
Very little of the host: a probe idles on a fraction of a core and a few tens of MB of RAM.

One probe per site. A probe measures from where it runs, so put one at each location whose paths you want to see. Your plan includes a set number of sites; add more from the targets screen or your account panel.

Install it

Open your Customer dashboard and go to Sites (or Add a site).
Name the site and copy the enrollment command it shows you. The command already contains this site's key — it is unique to that site and enrolls it to your account.
Paste the command on the host at that site and run it. The probe pulls the squidgrid/probe image and starts.
Within a minute the site shows checked in on the dashboard. Measurements begin on the next cycle.

The command your dashboard gives you is ready to paste. It looks like this — use the exact line from the dashboard, which has your site's key filled in:

docker run -d --name squidgrid-probe \
  --restart unless-stopped \
  --cap-drop ALL \
  -e SQUIDGRID_ENROLL=<your-site-key> \
  squidgrid/probe

Podman is identical — substitute podman for docker. The image is public on Docker Hub and you are welcome to inspect it before you run it.

Confirm it is measuring

On the dashboard the site moves to checked in, and its first readings appear once it has run a few measurement cycles. If a site stays pending for more than a few minutes, it is almost always outbound 443 being blocked — check that the host can reach the internet over HTTPS. Nothing needs to reach in to the probe.

What the probe does and does not do

Does	Does not
Measures the destinations you configure	Touch your internal network unless you point it there
Sends measurements only, outbound over HTTPS	Open any inbound port or listen for connections
Runs unprivileged, capabilities dropped	Run as root or need elevated privileges
Records latency, loss, jitter and the route	Capture, store or inspect your traffic

The full detail of what the fleet sends and at what rate is on how our probes measure, and the trust boundary is on the security model page.

Updating and removing

To update, pull the image and re-run the same command — the site keeps its identity and history. To remove a probe entirely, stop and delete the container (docker rm -f squidgrid-probe). That is the whole uninstall: nothing is left on the host, and the site simply stops reporting.

Next: Add targets & link sites · Reading your dashboard · back to all guides