CURLOPT_IPRESOLVE(3) Library Functions Manual CURLOPT_IPRESOLVE(3) NAME CURLOPT_IPRESOLVE - IP protocol version to use SYNOPSIS #include CURLcode curl_easy_setopt(CURL *handle, CURLOPT_IPRESOLVE, long resolve); DESCRIPTION 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 hostnames that resolve to more than one IP family. If the URL provided for a transfer contains a numerical IP version as a host name, this option does not override or prohibit libcurl from using that IP version. Available values for this option 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. DEFAULT CURL_IPRESOLVE_WHATEVER PROTOCOLS This functionality affects all supported protocols EXAMPLE int main(void) { CURL *curl = curl_easy_init(); if(curl) { CURLcode res; 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); res = curl_easy_perform(curl); curl_easy_cleanup(curl); } } AVAILABILITY Added in curl 7.10.8 RETURN VALUE Returns CURLE_OK SEE ALSO CURLOPT_HTTP_VERSION(3), CURLOPT_RESOLVE(3), CURLOPT_SSLVERSION(3) libcurl 2024-12-12 CURLOPT_IPRESOLVE(3)