PCC Doubt

Hi everyone, i´m trying to understand this lines about PCC:

add chain=output connection-mark=wlan1_conn action=mark-routing new-routing-mark=to_wlan1
add chain=output connection-mark=wlan2_conn action=mark-routing new-routing-mark=to_wlan2


why are they changing the routing mark in the OUTPUT chain if there is no router decision after that chain.

Thanks in advance.

That is so the router itself knows and remembers what route to use to respond back to connections coming into it, otherwise it falls through the default route, and when having multiple WAN connections that means any connections coming into the router on the “wrong” WAN interface generates a broken connection since it’s replying back with the wrong IP and route. Output chain is for traffic that the router itself is sending out.