How to fix ipfilter ignoring ipf.conf rules

In 2021 I noticed that I could manually aplly /etc/ipf/ipf.conf rules, but upon a restart of the ipfilter service they were not loaded.

This is explained somewhat in svc.ipfd(1m), as noted in this blog. In summary, by default the rules are expected to be described as SMF properties for the ipfilter service.

To tell it to intead load /etc/ipf/ipf.conf (as pointed to by default in another SMF property) we must run:

svccfg -s ipfilter:default setprop firewall_config_default/policy = astring: "custom"