Mini tutorial for DSA network config

In the swconfig world, and most applications of hardware switching, this is called a port mirror. Searching on that term would be more productive than "tap."

Packets entering and/or leaving an active port are also copied by hardware to output on another port, which is connected to an input-only monitoring device to examine their contents. This is different than a regular switch or bridge, which selectively copies based on examining the destination MAC address.

As noted in the article it is supported by swconfig if the hardware is compatible.