rc.order wrong (ipfw)

[Jeremy Chadwick]

On Fri, Mar 16, 2007 at 08:33:01PM -0300, JoaoBR wrote:
> On Friday 16 March 2007 18:50, Jeremy Chadwick wrote:
> > Okay, imagine this order:
> >
> > 1) Kernel starts
> > 2) Network driver is loaded
> > 3) Link is brought up
> > 4) Interface is configured for IP (manually or via DHCP)
> > 5) Firewall rules (ipfw or pf) are applied
> >
> > Do you realise that between steps #4 and steps #5 there is a small
> > window of time where someone may be able to send packets to your machine
> > and get responses which would normally be blocked by ipfw/pf?
> 
> nono that is not exactly how it works
> 
> unless you change ipfw's default behaviour which is deny all from any to any, 
> nothing goes to this machine because by default everything is blocked until 
> you permit it

You're absolutely correct, however your original post seems to have
taken many of us by surprise, causing some of us (at least me!) to
assume that you've changed the default method to allow.  I'm obviously
misunderstanding, so I apologise for that, but I hope you can see the
reasoning behind my comments with what I knew at the time.  :)

-- 
| Jeremy Chadwick                                    jdc at parodius.com |
| Parodius Networking                           http://www.parodius.com/ |
| UNIX Systems Administrator                      Mountain View, CA, USA |
| Making life hard for others since 1977.                  PGP: 4BD6C0CB |