Connectivity issues after suspend/hibernate

As @akwizgran pointed out here:

I think Linux takes network interfaces down on suspend/hibernate (wake-on-LAN is handled at the hardware level), so we might need to listen for some kind of event indicating that the device has come out of suspend/hibernate and force a connectivity check. Such events exist on certain flavours of Linux but I don't know how they're implemented (dbus?) or whether anything similar exists on Win/Mac.

I think we also already got reports that briar desktop was offline after coming back from suspend also it appeared online in the own user interface.