---
title: uuid.dns
summary: null
url: https://www.fastly.com/documentation/reference/vcl/functions/uuid/uuid-dns
---

```
STRING uuid.dns()
```

**Available in:** all subroutines

Returns the [RFC 4122](https://tools.ietf.org/html/rfc4122) identifier
of the DNS namespace, namely the constant 
`6ba7b810-9dad-11d1-80b4-00c04fd430c8`.

## Example

```vcl
declare local var.dns STRING;
set var.dns = uuid.version3(uuid.dns(), "www.example.com");
# var.dns is now "5df41881-3aed-3515-88a7-2f4a814cf09e"
```