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

# Troubleshooting

## Logging

iroh uses the `tracing` crate for logging. To see what's happening inside iroh, you need to enable logging in your application.

### Setup

First, add the tracing subscriber dependency:

```bash theme={null}
cargo add tracing-subscriber
```

Then, at the top of your `main` function, initialize the subscriber:

```rust theme={null}
#[tokio::main]
async fn main() -> anyhow::Result<()> {
    tracing_subscriber::fmt::init();
    
    // ...existing code...
}
```

### Running with logs

Now run your application with the `RUST_LOG` environment variable to control the log level:

```bash theme={null}
# For general info logs from iroh
RUST_LOG=iroh=info cargo run

# For more detailed debug logs if you need more information
RUST_LOG=iroh=debug cargo run
```

This will print log messages to your terminal, helping you understand what iroh is doing and diagnose any issues.

## Doctor CLI

[iroh doctor](https://github.com/n0-computer/iroh-doctor) is a command-line tool that helps you diagnose network connectivity issues with your iroh setup.

### Installation

```
cargo install iroh-doctor
```

### Home Relay

All iroh endpoints will maintain a single home relay server that they're
reachable at. On startup iroh will probe its configured relays & choose the one
with the lowest latency.

Report on the current network environment, using either an explicitly provided
stun host or the settings from the config file by using `iroh-doctor report`.

```shell theme={null}
iroh-doctor report
```

An example output looks like this:

```
getting report using relay map RelayMap {
    nodes: {
        RelayUrl(
            "https://aps1-1.relay.iroh.network./",
        ): RelayNode {
            url: RelayUrl(
                "https://aps1-1.relay.iroh.network./",
            ),
            stun_only: false,
            stun_port: 3478,
        },
        ...
    },
}
Report {
    udp: true,
    ipv6: true,
    ipv4: true,
    ipv6_can_send: true,
    ipv4_can_send: true,
    os_has_ipv6: true,
    icmpv4: None,
    icmpv6: None,
    mapping_varies_by_dest_ip: Some(false),
    mapping_varies_by_dest_ipv6: Some(false),
    hair_pinning: Some(false),
    portmap_probe: Some(
        ProbeOutput {
            upnp: false,
            pcp: false,
            nat_pmp: false,
        },
    ),
    preferred_relay: Some(
        RelayUrl(
            "https://use1-1.relay.iroh.network./",
        ),
    ),
    relay_latency: RelayLatencies(
        {
            RelayUrl(
                "https://aps1-1.relay.iroh.network./",
            ): 229.446041ms,
            RelayUrl(
                "https://euw1-1.relay.iroh.network./",
            ): 98.979167ms,
            RelayUrl(
                "https://use1-1.relay.iroh.network./",
            ): 10.133208ms,
        },
    ),
    relay_v4_latency: RelayLatencies(
        {
            RelayUrl(
                "https://aps1-1.relay.iroh.network./",
            ): 229.446041ms,
            ...
        },
    ),
    relay_v6_latency: RelayLatencies(
        {
            RelayUrl(
                "https://aps1-1.relay.iroh.network./",
            ): 238.579417ms,
            ...
        },
    ),
    global_v4: Some(72.**.**.**:54696),
    global_v6: Some([2600:**:**:***::100b]:53549),
    captive_portal: None,
}
```

The above output shows that the endpoint is using the `use1-1.relay.iroh.network` relay, and that it has a latency of 10ms. This is the relay that the endpoint will use to establish connections with other endpoints.

## Network Diagnostics

To diagnose connectivity issues on your users' endpoints in production, use [Network Diagnostics](/iroh-services/net-diagnostics/usage). It runs the same kinds of probes as `iroh-doctor` (UDP connectivity, NAT type, relay latency, port mapping) but you trigger them from the Iroh Services dashboard against any of your project's online endpoints. The report comes back to the dashboard, so you can see what your user is experiencing without asking them to run a CLI tool.

To enable diagnostics on an endpoint, grant the `NetDiagnosticsCap::GetAny` capability and run a `ClientHost`. See the [Network Diagnostics integration guide](/iroh-services/net-diagnostics/usage) for the full setup.