Keep It Simple: What Is Your Local Network, Anyway?

interface:network - the network connected to interface

Your local net could be

localnet = $int_if:network

or network as 192.168.100.0/24, or 2001:16d8:dead:beef::/64 or a list of networks -

sample filtering rule:

pass inet proto tcp from $localnet to any port $ports keep state

Make it as simple as possible, but no simpler