/ip firewall mangle
add chain=output out-interface=ether5 dscp=4 action=mark-packet new-packet-mark=proxy-hit passthrough=no
add chain=prerouting in-interface=ether5 src-address=192.168.10.0/24 action=mark-packet new-packet-mark=test-up passthrough=no
add chain=forward src-address=192.168.10.0/24 action=mark-connection new-connection-mark=test-conn passthrough=yes
add chain=forward in-interface=ether4 connection-mark=test-conn action=mark-packet new-packet-mark=test-down passthrough=no
add chain=output out-interface=ether5 dst-address=192.168.10.0/24 action=mark-packet new-packet-mark=test-down passthrough=no