switch connects all ports on boot

https://github.com/armbian/build/issues/511#issuecomment-258647387

uart

Connect your UART adapter here:

UART0-RX: J13-P01
UART0-TX: J13-P02
GND: J12-P08

                          GND TX RX
             J12   o  o  o  o  o  o
{SD slot}          o  o  o  o

switch

https://www.mail-archive.com/netdev@vger.kernel.org/msg150526.html

port mirroring

https://www.mail-archive.com/netdev@vger.kernel.org/msg150526.html

# ingress
      tc qdisc  add dev eth1 handle ffff: ingress
      tc filter add dev eth1 parent ffff:           \
               matchall skip_sw                      \
               action mirred egress mirror           \
               dev eth2
# egress
      tc qdisc add dev eth1 handle 1: root prio
      tc filter add dev eth1 parent 1:               \
               matchall skip_sw                       \
               action mirred egress mirror            \
               dev eth2