The book of pf...

[matteo filippetto]

>
> Because Peter made mention on misc@ that the second edition was geared
> towards OpenBSD 4.8 and the version of pf that's in FreeBSD is quite a
> bit older.
>
> http://marc.info/?l=openbsd-misc&m=128938065524891&w=2
>
Hi

In the second edition there are also reference and syntax of previous
version of pf ( < 4.8 ).

Best regards
-- 
Matteo Filippetto
http://op83.blogspot.com