---
name: "CURLOPT_DNS_SERVERS"
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_DNS_SERVERS"
---

# CURLOPT\_DNS\_SERVERS(3)

DNS servers to use

## NAME

CURLOPT\_DNS\_SERVERS - DNS servers to use

## SYNOPSIS

```
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_DNS_SERVERS, char *servers);
```

## DESCRIPTION

Pass a char pointer that is the list of DNS servers to be used instead of the system default. The format of the dns servers option is:

host\[:port\]\[,host\[:port\]\]...

For example:

192\.168.1.100,192.168.1.101,3.4.5.6

The application does not have to keep the string around after setting this option.

## DEFAULT

NULL - use system default

## PROTOCOLS

All

## EXAMPLE

```
int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode res;
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/foo.bin");
    curl_easy_setopt(curl, CURLOPT_DNS_SERVERS,
                     "192.168.1.100:53,192.168.1.101");
    res = curl_easy_perform(curl);
    curl_easy_cleanup(curl);
  }
}
```

## AVAILABILITY

This option requires that libcurl was built with a resolver backend that supports this operation. The c-ares backend is the only such one.

Added in 7.24.0

## RETURN VALUE

Returns CURLE\_OK if the option is supported, CURLE\_UNKNOWN\_OPTION if not, CURLE\_NOT\_BUILT\_IN if support was disabled at compile-time, CURLE\_BAD\_FUNCTION\_ARGUMENT when given an invalid server list, or CURLE\_OUT\_OF\_MEMORY if there was insufficient heap space.

## SEE ALSO

[**CURLOPT\_DNS\_CACHE\_TIMEOUT**(3)](/CURLOPT_DNS_CACHE_TIMEOUT/3.md), [**CURLOPT\_DNS\_LOCAL\_IP4**(3)](/CURLOPT_DNS_LOCAL_IP4/3.md), [**CURLOPT\_DNS\_LOCAL\_IP6**(3)](/CURLOPT_DNS_LOCAL_IP6/3.md)