I've been using ipfilter for the past two decades or so, but given its state I'm trying to switch to NPF on a server. The system in question has several network cards, each for a dedicated service bound to just one particular card. They are all directly connected to the Internet.
However, I’m currently struggling with getting a simple port forwarding working. All I want to do is forward all inbound traffic to port 22 on my wm3 interface to port 2222 on the same interface (i. e. the same IP address). One would think it should be straight forward, but a simple
map wm3 dynamic $wm3_ip 2222 <- $wm3_ip port 22
did not exactly yield the desired results (i. e. it did nothing). Any idea what I’m doing wrong?