Depends on how you configure it. In resolv.conf systems for example you can set a timeout of say 1 second and do it as main/reserve, or set it up to round-robin

Depends on how you configure it. In resolv.conf systems for example you can set a timeout of say 1 second and do it as main/reserve, or set it up to round-robin. From memory it's something like "options:rotate" If you have a more advanced local resolver of some sort (systemd for example) you can configure whatever behaviour you want.