CURLOPT_DNS_LOCAL_IP6(3)   Library Functions Manual   CURLOPT_DNS_LOCAL_IP6(3)

NAME
       CURLOPT_DNS_LOCAL_IP6 - IPv6 address to bind DNS resolves to

SYNOPSIS
       #include <curl/curl.h>

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_DNS_LOCAL_IP6, char *address);

DESCRIPTION
       Set the local IPv6 address that the resolver should bind to. The
       argument should be of type char * and contain a single IPv6 address as
       a string. Set this option to NULL to use the default setting (do not
       bind to a specific IP address).

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

       Using this option multiple times makes the last set string override the
       previous ones. Set it to NULL to disable its use again.

DEFAULT
       NULL

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");
           curl_easy_setopt(curl, CURLOPT_DNS_LOCAL_IP6, "fe80::a9ff:fe46:b619");
           res = curl_easy_perform(curl);
           curl_easy_cleanup(curl);
         }
       }

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

AVAILABILITY
       Added in curl 7.33.0

RETURN VALUE
       curl_easy_setopt(3) returns a CURLcode indicating success or error.

       CURLE_OK (0) means everything was OK, non-zero means an error occurred,
       see libcurl-errors(3).

SEE ALSO
       CURLOPT_DNS_INTERFACE(3), CURLOPT_DNS_LOCAL_IP4(3),
       CURLOPT_DNS_SERVERS(3)

libcurl                           2025-06-04          CURLOPT_DNS_LOCAL_IP6(3)