I know that I've encountered an answer to this question before, but I can't seem to figure out the right search terms to find the answer anywhere.
I have an Epson WF4630 at my office and an Epson 845 printer at home. Both are on wired networks.
Every time I log into any Ubuntu system or VM (12.04, 14.04, 14.10) on the local network, and most times I insert or remove a USB device (flash drive, webcam, fpga board... anything) my network printer 'spools'—it sounds like clearing the paper path and then moving and re-homing the print head.
Wireshark confirms stuff happens: every time I plug or unplug a usb device, i see BJNP and MDNS traffic broadcast, and then a TCP connection to the printer.
So the question is: what causes that to happen, and how can I disable it?