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Whether to shuffle DNS addresses.

Component Version macOS Windows Linux Server iOS SDK
CURL 8.2 ✅ Yes ✅ Yes ✅ Yes ✅ Yes ✅ Yes
MBS( "CURL.SetOptionDNSShuffleAddresses"; curl; Value )   More


Parameter Description Example
curl The CURL session handle. $curl
Value The new setting, 1 or 0 1


Returns OK or error.


Whether to shuffle DNS addresses.
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. CURL.SetOptionDNSCacheTimeout 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 is 0.

See also DNS_SHUFFLE_ADDRESSES option in CURL manual.

See also

Release notes

Blog Entries

Created 16th May 2018, last changed 16th May 2018

CURL.SetOptionDNSServers - CURL.SetOptionDOHSSLVerifyHost