verrevpath -- ipfw: unknown argument ``not''

[Lowell Gilbert]

Mark Edwards <mark at antsclimbtree.com> writes:

> I am trying to implement the verrevpath suggestion in the ipfw man
> page, as follows:
> 
> >      The verrevpath option could be used to do automated anti-
> > spoofing by
> >      adding the following to the top of a ruleset:
> >
> >            ipfw add deny ip from any to any not verrevpath in
> 
> However, when I try to add the rule, I get an error:
> 
> > lilbuddy:~ paimin$ ipfw add deny ip from any to any not verrevpath in
> > ipfw: unknown argument ``not''
> 
> Can someone tell what is causing this syntax to fail?  Thanks!

Works fine for me right now on -STABLE (RELENG_6).
You didn't mention what you were running, so there's not much else we
can tell you.