> ## Documentation Index
> Fetch the complete documentation index at: https://ngrok.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Diagnose

> Learn how to diagnose the ngrok agent's connectivity issues.

The `ngrok diagnose` command runs a series of tests to diagnose potential connectivity issues between the ngrok agent and the remote ngrok service. See available flags [here](/agent/cli/#ngrok-diagnose).

## Diagnostics

The diagnose command gathers your environment information, including your sanitized configuration file. It then tests:

* proxy connectivity, if `proxy_url` is configured
* name resolution
* general internet connectivity

By default, `ngrok diagnose` tests IPv4 connectivity between the ngrok agent and the closest ngrok point of presence. To test IPv6 connectivity, add `--ipv6 true` to the command. To test connectivity between the ngrok agent and all ngrok points of presence, add `--region all`.

### Basic output

The diagnose command prints a connectivity summary in your terminal. If you have full connectivity, your report will look like this:

```bash theme={null}
Testing ngrok connectivity...

Internet Connectivity
  Name Resolution                           [ OK ]
  TCP                                       [ OK ]
  TLS                                       [ OK ]
Localhost Connectivity
  Name Resolution                           [ OK ]
ngrok Connectivity - Region: Auto (lowest latency)
  Name Resolution                           [ OK ]
  TCP                                       [ OK ]
  TLS                                       [ OK ]
  Tunnel Protocol                           [ OK ]
Successfully established ngrok connection! (region: 'auto', latency: 54.895145ms)
```

If there's a connectivity problem, your report will show warnings and errors that need to resolved before ngrok can work correctly:

```
Testing ngrok connectivity...

Internet Connectivity
  Name Resolution                         [ WARN ]
  TCP                                       [ OK ]
  TLS                                       [ OK ]

Errors and warnings encountered during diagnostics:

* Diagnostics
  * Name Resolution
    * Resolver: system
      * Hostname: google.com
        - Err: Failed to resolve host google.com: lookup google.com on
               [::1]:53: read udp [::1]:48848->[::1]:53: read: connection
               refused
               (NGROK_ERR_8000)

Error establishing ngrok connection:
Failed to establish internet connectivity: resolver returned no IPs.
```

### Verbose output

For more detailed output, you can use the `--write-report`/`-w` flag to generate a verbose report:

```bash theme={null}
ngrok diagnose -w out.txt
```

By default, `ngrok diagnose --region all` will generate a report. The `diagnose` output will print the report location:

```
Report written to /var/folders/yg/yzt44t813/T/ngrok-diagnose1080549118/diagnose.json
```

### Kubernetes

You can run `ngrok diagnose` within your Kubernetes cluster to troubleshoot network connectivity issues. See [Testing in a Kubernetes Cluster](/guides/running-behind-firewalls/#testing-in-a-kubernetes-cluster).