---
name: "CURLOPT_ADDRESS_SCOPE"
section: "3"
platform: "macos"
package: "curl"
version: "166.0.0.0.1"
release: "macOS 26.5"
platforms: ["linux", "macos"]
url: "https://new.carta.tech/CURLOPT_ADDRESS_SCOPE"
---

# CURLOPT\_ADDRESS\_SCOPE(3)

scope id for IPv6 addresses

## NAME

CURLOPT\_ADDRESS\_SCOPE - scope id for IPv6 addresses

## SYNOPSIS

```
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_ADDRESS_SCOPE, long scope);
```

## DESCRIPTION

Pass a long specifying the scope id value to use when connecting to IPv6 addresses.

## DEFAULT

0

## PROTOCOLS

All, when using IPv6

## EXAMPLE

```
#include <net/if.h> /* for if_nametoindex() */
int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode ret;
    long my_scope_id;
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
    my_scope_id = if_nametoindex("eth0");
    curl_easy_setopt(curl, CURLOPT_ADDRESS_SCOPE, my_scope_id);
    ret = curl_easy_perform(curl);
    curl_easy_cleanup(curl);
  }
}
```

## AVAILABILITY

Added in 7.19.0

## RETURN VALUE

Returns CURLE\_OK if the option is supported, and CURLE\_UNKNOWN\_OPTION if not. Returns CURLE\_BAD\_FUNCTION\_ARGUMENT if set to a negative value.

## SEE ALSO

[**CURLOPT\_DEBUGFUNCTION**(3)](/CURLOPT_DEBUGFUNCTION/3.md), [**CURLOPT\_STDERR**(3)](/CURLOPT_STDERR/3.md)