---
title: "Network and resource requirements | Grafana Cloud documentation"
description: "Review Synthetic Monitoring private probe firewall access for service connections, script imports, and monitored targets, and estimate CPU and memory requirements."
---

> For a curated documentation index, see [llms.txt](/llms.txt). For the complete documentation index, see [llms-full.txt](/llms-full.txt).

# Network and resource requirements

Before [setting up a Synthetic Monitoring private probe](/docs/grafana-cloud/observe-and-act/testing/synthetic-monitoring/set-up/set-up-private-probes/set-up/), review the connections it needs and estimate CPU and memory for your checks. Use these requirements to prepare the host or container environment and its firewall rules.

## Firewall configuration

Private probes initiate connections to Synthetic Monitoring services and monitored targets. Configure the probe host’s firewall to allow the outbound connections in the following sections. If a monitored target has its own firewall, configure that firewall separately to allow inbound connections from the probe host.

### Synthetic Monitoring services

- Allow outbound connections from the probe host to the addresses in the “API server URL” column of the [regional endpoint table](/docs/grafana-cloud/observe-and-act/testing/synthetic-monitoring/set-up/set-up-private-probes/set-up/#probe-api-server-url).
- Allow outbound connections from the probe host to the addresses in the “Secrets proxy” column of the [regional endpoint table](/docs/grafana-cloud/observe-and-act/testing/synthetic-monitoring/set-up/set-up-private-probes/set-up/#probe-api-server-url).

### Prometheus and Loki instances

Allow outbound connections from the probe host to the Prometheus server URL and the Loki URL:

1. Log in to Grafana Cloud and open your stack.
2. Navigate to **Home** > **Testing & synthetics** > **Synthetics** > [**Config**](/launch/a/grafana-synthetic-monitoring-app/config).
3. Under the **General** tab, scroll down to **Data sources**.
4. For the Prometheus server URL:
   
   1. Click the Prometheus data source. For example: `grafanacloud-STACK_NAME-prom`.
   2. Copy the **Prometheus server URL** under the **Settings** tab -> **Connection**.
5. For the Loki URL:
   
   1. Click the Loki data source. For example: `grafanacloud-STACK_NAME-logs`.
   2. Copy the **URL** under the **Settings** tab -> **Connection**.
6. Update the probe host’s firewall rules with both URLs.

### External script imports

- If you use k6 scripts that import external modules, for example, k6 modules from `jslib.k6.io`, allow outbound connections from the probe host to the module hosts.

> Note
> 
> MultiHTTP test executions make outbound connections to `jslib.k6.io` when run. If you run MultiHTTP checks on private probes behind a firewall, allow outbound connections from the probe host to `jslib.k6.io`.

### Monitored targets

Allow outbound connections from the probe host to each monitored target. The required protocol depends on the check type. For example:

- ICMP: for ping and traceroute checks.
- UDP or TCP: for DNS checks.
- TCP: for HTTP and MultiHTTP checks.

If a target’s firewall blocks these connections, configure the target’s firewall, not the probe host’s firewall, to allow inbound connections from the probe host over the required protocol.

## Calculate resource requirements

Resources used by private probes may vary based on the targets being monitored, so it can be hard to predict them in advance. Below, we provide a rough estimate to get you started.

The baseline CPU and memory resources, if you want to run:

- API endpoint checks: `50m`/`64Mi`.
- The above, plus multi-step checks, scripted checks, or both: `200m`/`256Mi`.
- The above, plus browser checks: `1000m`/`1024Mi`.

Then, for each check per minute of the following types, add:

- API endpoint (HTTP, Ping, DNS, TCP, Traceroute): `5m`/`2Mi`.
- Multi-step or scripted checks: `20m`/`32Mi`
- Browser checks: `100m`/`256Mi`.

As mentioned above, keep in mind that these are ballpark estimates. Monitor the resource usage of your probe, and stay on the lookout for CPU throttling and OOM events to see if you need to adjust any resources.

## Next steps

Continue with [Set up a private probe](/docs/grafana-cloud/observe-and-act/testing/synthetic-monitoring/set-up/set-up-private-probes/set-up/) to register a probe, or [install the agent](/docs/grafana-cloud/observe-and-act/testing/synthetic-monitoring/set-up/set-up-private-probes/set-up/#install-the-agent) if you already have a probe authentication token.