CURLOPT_DNS_SHUFFLE_ADDRESSES - shuffle IP addresses for hostname
#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_DNS_SHUFFLE_ADDRESSES, long onoff);
curl_easy_setopt options CURLOPT_DNS_SHUFFLE_ADDRESSES(3)
NAME
CURLOPT_DNS_SHUFFLE_ADDRESSES - shuffle IP addresses for hostname
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, shuf-
fle the order of all returned addresses so that they will be used in a
random order. This is similar to the ordering behavior of gethostby-
name 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 implementa-
tion. 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.
ATTRIBUTES
See attributes(7) for descriptions of the following attributes:
+---------------+------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+------------------+
|Availability | web/curl |
+---------------+------------------+
|Stability | Uncommitted |
+---------------+------------------+
SEE ALSO
CURLOPT_DNS_CACHE_TIMEOUT(3), CURLOPT_IPRESOLVE(3),
NOTES
Source code for open source software components in Oracle Solaris can
be found at https://www.oracle.com/downloads/opensource/solaris-source-
code-downloads.html.
This software was built from source available at
https://github.com/oracle/solaris-userland. The original community
source was downloaded from https://curl.se/down-
load/curl-7.83.1.tar.bz2.
Further information about this software can be found on the open source
community website at http://curl.haxx.se/.
libcurl 7.83.1 September 08, 2021
CURLOPT_DNS_SHUFFLE_ADDRESSES(3)