The journal records the network state of the host and each change of
that state. The support team reads one file to see the interfaces, the
routes, the resolvers, and the recoveries around an incident. The same
file shows the health of the query path. A change that touches only
AirDrop or virtual interfaces runs no DNS work.
Previously, a valid interfaces map is only meaningful on Windows and
Darwin, where ctrld needs to set DNS for all physical interfaces.
With new network monitor, the valid interfaces is used for checking new
changes, thus we have to implement the valid interfaces map for all
systems.
- On Linux, just retrieving all non-virtual interfaces.
- On others, fallback to use default route interface only.
Anthony Wong