> For the complete documentation index, see [llms.txt](https://docs.dnscontrol.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.dnscontrol.org/language-reference/domain-modifiers/service-provider-specific/mikrotik-routeros/mikrotik_nxdomain.md).

# MIKROTIK\_NXDOMAIN

`MIKROTIK_NXDOMAIN` creates a RouterOS NXDOMAIN static entry. The router will respond with NXDOMAIN for any DNS queries matching the specified name. This is commonly used for DNS-based ad blocking or blackholing.

See the [MikroTik RouterOS provider page](/provider/mikrotik.md) for full configuration details.

Metadata keys supported:

| Key               | Description                                           |
| ----------------- | ----------------------------------------------------- |
| `match_subdomain` | Set to `"true"` to also match subdomains of the name. |
| `regexp`          | RouterOS regexp for query matching.                   |
| `comment`         | Comment stored on the RouterOS record.                |

{% code title="dnsconfig.js" %}

```javascript
D("example.com", REG_MY_PROVIDER, DnsProvider(DSP_MY_PROVIDER),
    // Block ads.example.com with NXDOMAIN.
    MIKROTIK_NXDOMAIN("ads"),

    // Block tracking.example.com and all its subdomains.
    MIKROTIK_NXDOMAIN("tracking", {match_subdomain: "true"}),
);
```

{% endcode %}