# DNS Security Check

With the **Security** check, you can test your DNS environment for vulnerabilities.

### Usage <a href="#dnssecuritycheck-usage" id="dnssecuritycheck-usage"></a>

The flaws the Security check looks for are:

* Whether the name server is an [open resolver](https://apica-kb.atlassian.net/wiki/spaces/ASMDOCS/pages/4632274/Open+Resolver).
* Whether the name server presents its software and version.
* Whether the name server allows [zone transfers](https://apica-kb.atlassian.net/wiki/spaces/ASMDOCS/pages/4632468/Zone+Transfer) globally.

Any one of these three security vulnerabilities could mean you are at risk and the vulnerability should be addressed.

Each control point of the check can be either `pass`, `fail` or be `inconclusive`.

If all control points pass, the check will report an `Information` message as the name server is correctly configured.

If one or more check fails, the check will report this as a `Warning` or an `Error` message. This means that measures should be taken to fix the potential security flaw.

A control point can also report `Inconclusive` which mean that the control point receives such information that the check can’t determine if there is a security problem. The message will give some information on what the check has encountered.


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# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.apica.io/platform-docs/synthetic-monitoring-overview/explore-the-platform/check-types/dns-security-check.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.