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Date: Mon, 10 Jun 1996 09:32:44 -0500
From: Alex Nash <alex@fa.tdktca.com>
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To: didier@omnix.fr.org
CC: hackers@freebsd.org
Subject: Re: firewall (ipfw)
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didier@omnix.fr.org wrote:
> 
> The company I'm working for plan to install a permanent acces to internet
> through an analogic leased line and two 32kb modems.
> 
> to protect our application in plan to install the firewall builtin FreeBSD
> 
> I've never used ipfw and I dont have any experience with firewalls.
> 
> could you tell me how I could set up this machine

>From /etc/rc.firewall (in -current):

# If you don't know enough about packet filtering, we suggest that you
# take time to read this book:
#
#       Building Internet Firewalls
#       Brent Chapman and Elizabeth Zwicky
#
#       O'Reilly & Associates, Inc
#       ISBN 1-56592-124-0
#
# For a more advanced treatment of Internet Security read:
#
#       Firewalls & Internet Security
#       Repelling the wily hacker
#       William R. Cheswick, Steven M. Bellowin
#
#       Addison-Wesley
#       ISBN 0-201-6337-4

There is also an excellent firewall discussion in the handbook.  See
section 6.4, currently available at:

    http://www.freebsd.org/handbook/handbook71.html#73

Note that the syntax of ipfw has changed from that documented in
the handbook (I'm working on it, really!).  To get acquainted with
the new syntax:

   - type ipfw without any arguments to see the usage
   - look at ipfw(8) <-- I'm fixing this one too
   - and peruse /etc/rc.firewall in -current.

BTW, this probably should be moved to freebsd-security.  Alternatively,
I'd be happy to discuss this with you off-line.

Alex