Does loop back interface generates interrupt on NIC/Hardware

Question

Does loop back interface generates interrupt on NIC/Hardware

Answer 1

The loopback interface is a virtual network interface. It doesn't correspond to any actual hardware, and packets transmitted through it therefore do not generate hardware interrupts.

It's possible that linux has some concept of a "soft interrupt", i.e. an inter-thread/process signalling mechanism, and that packets over the loopback will cause these. Older Linux versions definitely had these "soft interrupts", but I'm not sure if the 2.6 series does, and I'm not sure if packets over the loopback do or ever did generate them.