CURLOPT_IPRESOLVE

#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_IPRESOLVE, long resolve);

Allows an application to select what kind of IP addresses to use when establishing a connection or choosing one from the connection pool. This is interesting when using host names that resolve addresses using more than one version of IP. The allowed values are:

CURL_IPRESOLVE_WHATEVER

Default, can use addresses of all IP versions that your system allows.

CURL_IPRESOLVE_V4

Uses only IPv4 addresses.

CURL_IPRESOLVE_V6

Uses only IPv6 addresses.

CURL_IPRESOLVE_WHATEVER

All

CURL *curl = curl_easy_init();
if(curl) {
  curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/foo.bin");
  /* of all addresses example.com resolves to, only IPv6 ones are used */
  curl_easy_setopt(curl, CURLOPT_IPRESOLVE, CURL_IPRESOLVE_V6);
  ret = curl_easy_perform(curl);
  curl_easy_cleanup(curl);
}

Always

Returns CURLE_OK

CURLOPT_HTTP_VERSION(3), CURLOPT_SSLVERSION(3),