.\" generated by cd2nroff 0.1 from CURLOPT_IPRESOLVE.md
.TH CURLOPT_IPRESOLVE 3 "2024-11-18" libcurl
.SH NAME
CURLOPT_IPRESOLVE \- IP protocol version to use
.SH SYNOPSIS
.nf
#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_IPRESOLVE, long resolve);
.fi
.SH 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:
.IP CURL_IPRESOLVE_WHATEVER
Default, can use addresses of all IP versions that your system allows.
.IP CURL_IPRESOLVE_V4
Uses only IPv4 addresses.
.IP CURL_IPRESOLVE_V6
Uses only IPv6 addresses.
.SH DEFAULT
CURL_IPRESOLVE_WHATEVER
.SH PROTOCOLS
This functionality affects all supported protocols
.SH EXAMPLE
.nf
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);
  }
}
.fi
.SH AVAILABILITY
Added in curl 7.10.8
.SH RETURN VALUE
Returns CURLE_OK
.SH SEE ALSO
.BR CURLOPT_HTTP_VERSION (3),
.BR CURLOPT_RESOLVE (3),
.BR CURLOPT_SSLVERSION (3)