---
title: addr.is_ipv6
summary: null
url: https://www.fastly.com/documentation/reference/vcl/functions/addr/addr-is-ipv6
---

```
BOOL addr.is_ipv6(IP ip)
```

**Available in:** all subroutines

Returns `true` if the address family of the given address is IPv6.

## Example

```vcl
if (addr.is_ipv4(client.ip)) {
  /* the client connected over IPv6 */
}
```