# Restrict access by IP address

IP restrictions decide where calls to a gateway can come from. You can set an allowlist, a blocklist and a list of blocked countries for a whole environment, and again for one key or user. The gateway checks them on every request, before anything else.

## Restrict an environment

To restrict every credential of an environment:

1. In the portal, go to [**Agent Gateway**](https://auth.faustine.ai/go?to=%2Fintegrations%2Fagent-gateway) and select your gateway.
2. Select the **Policies** tab and go to **IP Restrictions**.
3. In **IP allowlist**, enter the addresses that can reach the gateway, one IP address or CIDR range per line. IPv4 and IPv6 are accepted. Leave it empty to allow any address.
4. In **IP blocklist**, enter the addresses to refuse, one per line.
5. Under **Blocked countries**, turn on each country to refuse.
6. Select **Save changes**.

```text
203.0.113.10
10.0.0.0/8
2001:db8::/32
```

> **Warning:** An allowlist applies to every client of the environment at once. A person on claude.ai or ChatGPT calls from that service's servers, not from their own network, so an allowlist with only your office range refuses them.

## Restrict one key or user

To restrict a single credential:

1. In the gateway's **Access** tab, select **API keys** or **Users**, and select the credential.
2. Go to **IP Restrictions** and fill in the same three fields.
3. Select **Save changes**.

The allowlist is checked on every call. It does not apply to the sign-in page.

The credential's lists are added to the environment's. A call has to pass both. Countries blocked by the environment appear on the credential as **Blocked by the environment** and cannot be turned off there.

## How the lists combine

| Rule | Result |
| --- | --- |
| The address is on a blocklist | Refused with `ip_blocked`, even if it is also on an allowlist. |
| The address belongs to a blocked country | Refused with `ip_blocked`. |
| An allowlist is set and the address is not on it | Refused with `ip_not_allowed`. |
| No allowlist is set | Any address that is not blocked is accepted. |

Over REST the refusal is a `403`. The request appears in the gateway's **Logs** tab as denied, with the caller's address in the message.

## Blocked countries

The list holds four countries: Cuba, Iran, North Korea and Syria. All four are blocked by default on every gateway, and you can turn any of them off.

## Troubleshooting

| Symptom | Cause | Fix |
| --- | --- | --- |
| `Denied (ip_not_allowed): This gateway cannot be reached from <address>` | The environment has an allowlist and the caller is not on it. | Add the address shown in the message, or clear the allowlist. |
| `Denied (ip_not_allowed): This key cannot be used from <address>` | The key has an allowlist and the caller is not on it. | Add the address to the key's **IP allowlist**. |
| `Denied (ip_blocked): This gateway is blocked from <country>` | The caller's address belongs to a blocked country. | Turn the country off under **Blocked countries** if the block is not intended. |

## Next steps

- [Limits and quotas](https://docs.faustine.ai/agent-gateway/limits/): rate, quota and concurrency limits.
- [Logs](https://docs.faustine.ai/agent-gateway/logs/): find denied requests and their reason.
- [Gateway HTTP](https://docs.faustine.ai/reference/gateway-http/): the error codes a client receives.