PF firewall rules and documentation
freebsd-questions at herveybayaustralia.com.au
Sat Jan 29 02:42:42 UTC 2011
I spent some time playing with pf and pf.conf, and followed the
directions in the handbook. It redirected me to the openbsd site for
pf.conf, and recommended it as the most comprehensive documentation for pf.
Firstly, I didn't find that. I had to translate the instructions into
the current version used in FreeBSD, OpenBSD appears to be further
advanced than this based on the current docs.
Secondly, some of the rules don't appear to be following. From my
understanding based on the documentation in the handbook and on the site
pf is default allowing traffic. So explicit rules to block should be set
first and then rules set to allow what is needed in. Some assumptions
are made in the rules by the interpreter, so according to OpenBSD one
can (even in the older versions) simply state block and it is
interpreted as 'block on $interfaces all'. This turned out to not be the
I know this has come up before, but I think it might be time to document
pf.conf properly. It seems to be a bit of security risk not to. Users
may be mistaken in their belief of their security on the network using
pf, and may be less likely to trust again when it breaks.
More information about the freebsd-questions