If enabled, do not classify optimistic addresses as deprecated during source address selection. Preferred addresses will still be chosen before optimistic addresses, subject to other ranking in the source address selection algorithm. 0: disabled (default) 1: enabled
This will be enabled if at least one of conf/{all,interface}/use_optimistic is set to 1, disabled otherwise.
Nb: per interface setting (where “interface” is the name of your network interface); “all” is a special interface: changes the settings for all interfaces.
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