Up to now, it was not visible on D-Bus whether a connection was generated by NetworkManager and/or volatile.
That is for example interesting for firewalld, which aims to store persistant configuration in NetworkManager's profile. However, that doesn't make sense for external connections (which are nm-generated & volatile). In fact, it probably makes no sense for volatile connections in general, because modifying them, likely makes them non-volatile (depending on how the profile is modified).
Also, the Update2() D-Bus operation allows to carefully make connections volatile and unsaved. As we have public API to set these flags, we should also expose them on D-Bus.
aae483c0a settings: add NMSettingsConnectionFlags flags
libnm-core/nm-dbus-interface.h | 16 ++++++++++++++++
src/settings/nm-settings-connection.h | 17 ++++++++++++-----
2 files changed, 28 insertions(+), 5 deletions(-)