NAME

       CURLOPT_DNS_SHUFFLE_ADDRESSES - Shuffle addresses when a hostname returns more than one

SYNOPSIS

       #include <curl/curl.h>

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_DNS_SHUFFLE_ADDRESSES, long onoff);

DESCRIPTION

       When a name is resolved and more than one IP address is returned, shuffle the order of all
       returned addresses so that they will be used in a random order.  This is  similar  to  the
       ordering behavior of gethostbyname which is no longer used on most platforms.

       Addresses  will  not  be reshuffled if a name resolution is completed using the DNS cache.
       CURLOPT_DNS_CACHE_TIMEOUT(3) can be used together with this option  to  reduce  DNS  cache
       timeout or disable caching entirely if frequent reshuffling is needed.

       Since  the  addresses  returned  will  be  reordered  randomly, their order will not be in
       accordance with RFC 3484 or any other deterministic order that may  be  generated  by  the
       system's  name  resolution implementation. This may have performance impacts and may cause
       IPv4 to be used before IPv6 or vice versa.

DEFAULT

       0 (disabled)

PROTOCOLS

       All

EXAMPLE

       CURL *curl = curl_easy_init();
       if(curl) {
         curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
         curl_easy_setopt(curl, CURLOPT_DNS_SHUFFLE_ADDRESSES, 1L);

         curl_easy_perform(curl);

         /* always cleanup */
         curl_easy_cleanup(curl);
       }

AVAILABILITY

       Added in 7.60.0

RETURN VALUE

       CURLE_OK or an error such as CURLE_UNKNOWN_OPTION.

SEE ALSO

       CURLOPT_DNS_CACHE_TIMEOUT(3), CURLOPT_IPRESOLVE(3),