NetFlow working for physical/sub interfaces only?

Question

As far as I know, NetFlow can collect data from physical interfaces and its subinterfaces, right?

Not from loopback, VLAN, tunnel or any virtual interface.

Answer 1

That depends on the device. Some devices will let you collect NetFlow information on certain virtual interfaces, e.g. a Cisco 4K switch can have NetFlow on the port channel, and that is usually preferred over the individual channel member ports.

Also, a subinterface is a virtual interface.