The OP is somewhat mistaken about entropy sources within a modern system.
A modern OS implementation keeps a record of the number of shannons of entropy available in the
The only way to acquire more shannons of entropy to fill the
Such sources can include the timing information of key presses which introduce fractions of a shannon of entropy but network activity of any type is disturbingly periodic, hence such sources have largely been removed.
If you want a true random number generator you need something like an Entropy key which uses physical quantum phenomena to generate many shannons of entropy continuously.