> For the complete documentation index, see [llms.txt](https://docs.drizz.dev/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.drizz.dev/desktop-app/networks-and-preflight.md).

# Networks, proxies & preflight

Run the network preflight check, read its results, and work with corporate proxies and TLS inspection.

Preflight reports whether the desktop app can reach every service it needs, and names the layer that fails.

{% hint style="info" %}
`Help` → **Network Preflight**
{% endhint %}

|                        |                                                                                                                       |
| ---------------------- | --------------------------------------------------------------------------------------------------------------------- |
| **Platforms**          | macOS                                                                                                                 |
| **When it runs**       | Automatically before device setup, and any time you ask for it                                                        |
| **What "ready" means** | Every check shows **OK** and the connection status reads **Ready**                                                    |
| **Corporate TLS**      | Drizz reads the macOS system certificate store — no configuration needed when the root certificate is installed there |
| **Watch out**          | Works on a hotspot but not on office wifi means TLS inspection or an egress rule, not a Drizz fault                   |

## Prerequisites

* Drizz desktop app installed
* A network connection
* For corporate networks: the company root certificate in the macOS **system** keychain

## Run preflight

1. Open **Help → Network Preflight**.
2. Click **Run**. Drizz also runs this check automatically before desktop setup.
3. Read the **connection status** at the top.
4. Identify the rows that are not **OK**. Preflight names the specific service or network layer that failed.
5. Fix the topmost failing row. A failure high in the list explains the failures below it.
6. Click **Run** to re-execute the check.
7. Confirm every check shows **OK** and the status reads **Ready**, then click **Continue**.

## What it checks

Four layers, in the order they matter.

| Layer                 | What's being confirmed                                                            |
| --------------------- | --------------------------------------------------------------------------------- |
| **Network integrity** | DNS resolution, proxy routing, HTTPS reachability                                 |
| **Sign-in**           | That the identity services behind sign-in are reachable and your session is valid |
| **Platform services** | That the services which allocate devices and store your tests respond             |
| **Live connection**   | That the real-time channel used to stream device state and logs stays open        |

## Corporate networks, proxies and TLS inspection

Drizz reads the **macOS system certificate store**. On a network with a TLS-inspecting proxy, no configuration is required when the company root certificate is installed in the system keychain.

| Symptom                                               | Diagnosis                                                                                                                                                                 |
| ----------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Works on a phone hotspot, fails on the office network | **Cause:** TLS inspection or an egress rule. **Fix:** run preflight on both networks and compare which rows differ. That list goes to IT                                  |
| Preflight fails only on the corporate network         | **Cause:** the corporate root certificate is not in the macOS system keychain. **Fix:** install it in the system keychain, not a user keychain or a browser store         |
| Runs start and then die partway                       | **Cause:** a proxy terminating long-lived connections after a fixed idle period. **Fix:** exempt the real-time connection from the idle timeout                           |
| An automatic app update can't download                | **Cause:** the same egress rules that block sign-in. **Fix:** run preflight before treating the update as broken. See [Updates & forced updates](/desktop-app/updates.md) |

Checks to raise with IT when preflight fails on a corporate network:

* Is the corporate root certificate installed in the **system** keychain, not just a user keychain or a browser store?
* Is HTTPS egress to Drizz's domains allowed, including the real-time connection?
* Is there a proxy that terminates long-lived connections after a fixed idle period?

## Common mistakes

| What you do                                                  | What happens                                                           |
| ------------------------------------------------------------ | ---------------------------------------------------------------------- |
| Debug a failing run for an hour before running preflight     | Preflight would have named the failing layer in 20 seconds             |
| Assume "works on hotspot, not on office wifi" is a Drizz bug | It's TLS inspection or an egress rule. Take the preflight output to IT |
| Install the corporate certificate in a browser only          | Drizz reads the macOS system store. It needs to be there               |
| Re-run preflight without fixing anything                     | Same result. Fix the topmost red row, then re-run                      |
| Ignore an amber real-time connection row                     | Runs start and then die partway. That row is the reason                |
| Reinstall the app to fix a network problem                   | Nothing changes. The network is outside the app                        |

## Next

* [Download & install](/desktop-app/download-and-install.md)
* [Updates & forced updates](/desktop-app/updates.md)
* [Report an issue](/desktop-app/report-an-issue.md)

***

*Last updated: 6 August 2026*