dynamically updating anchors via pfctl

[Friso Seyferth]

is it correct that you have to reload the ruleset after adding a rule to 
an anchor like this?

echo "nat on ed0 inet from 172.16.55.2  to any -> ed0" | pfctl -a 
allownat:friso -f -

pfctl -F all ; pfctl -f 
/etc/pf.conf                                         

it's the only way that it seems to work, just adding the rule without 
reloading /flushing does nothing...

running freebsd and pf