In that case, Synapse would not point to any Coturn servers and audio/video call functionality may fail.
## Manually defining your public IP
In the `hosts` file we explicitly ask for your server's external IP address when defining `ansible_host`, because the same value is used for configuring Coturn.
If you'd rather use a local IP for `ansible_host`, make sure to set up `matrix_coturn_turn_external_ip_address` replacing `YOUR_PUBLIC_IP` with the pubic IP used by the server.
If you'd like to rely on external IP address auto-detection (not recommended unless you need it), set `matrix_coturn_turn_external_ip_address` to an empty value. The playbook will automatically contact an [EchoIP](https://github.com/mpolden/echoip)-compatible service (`https://ifconfig.co/json` by default) to determine your server's IP address. This API endpoint is configurable via the `matrix_coturn_turn_external_ip_address_auto_detection_echoip_service_url` variable.
If your server has multiple external IP addresses, the Coturn role offers a different variable for specifying them:
```yaml
# Note: matrix_coturn_turn_external_ip_addresses is different than matrix_coturn_turn_external_ip_address
# Controls whether SSL certificates will be validated when contacting the EchoIP service (matrix_coturn_turn_external_ip_address_auto_detection_echoip_service_url)
- when:"(result_matrix_coturn_turn_external_ip_address_auto_detection_echoip_response.failed or 'json' not in result_matrix_coturn_turn_external_ip_address_auto_detection_echoip_response)"
name:Fail if EchoIP service failed
ansible.builtin.fail:
msg:"Failed contacting EchoIP service API at `{{ matrix_coturn_turn_external_ip_address_auto_detection_echoip_service_url }}` (controlled by `matrix_coturn_turn_external_ip_address_auto_detection_echoip_service_url`). Full error: {{ result_matrix_coturn_turn_external_ip_address_auto_detection_echoip_response }}"