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

# How do I deal with network issues?

This page helps you resolve SSL and network errors that prevent W\&B from syncing your training data, so you can keep experiments running even on unreliable or restricted networks.

If you encounter SSL or network errors, such as `wandb: Network error (ConnectionError), entering retry loop`, use any of the following solutions:

* Upgrade the SSL certificate. On an Ubuntu server, run `update-ca-certificates`. A valid SSL certificate is required to sync training logs securely.
* If the network connection is unstable, operate in offline mode by setting the [optional environment variable](/models/track/environment-variables#optional-environment-variables) `WANDB_MODE` to `offline`, and sync files later from a device with internet access.
* Consider using [W\&B Private Hosting](/platform/hosting/), which runs locally and avoids syncing to cloud servers.

If you specifically see the `SSL CERTIFICATE_VERIFY_FAILED` error, the issue might stem from a company firewall intercepting traffic. Point the `requests` library at your local CA bundle so W\&B trusts the firewall's certificate:

```bash theme={null}
export REQUESTS_CA_BUNDLE=/etc/ssl/certs/ca-certificates.crt
```

***

<Badge stroke shape="pill" color="orange" size="md">[Connectivity](/support/models/tags/connectivity)</Badge>