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Date:      Fri, 30 Jul 1999 12:22:57 -0600
From:      Oscar Bonilla <obonilla@fisicc-ufm.edu>
To:        "David B. Aas" <dave@ciminot.com>
Cc:        questions@freebsd.org, obonilla@fisicc-ufm.edu
Subject:   Re: FW: Need consulting help with v3.2 firewall configuration
Message-ID:  <19990730122256.A1784@fisicc-ufm.edu>
In-Reply-To: <000401bed9ff$44528860$0fc8a8c0@dave.ciminot.com>; from David B. Aas on Thu, Jul 29, 1999 at 03:16:38PM -0500
References:  <000401bed9ff$44528860$0fc8a8c0@dave.ciminot.com>

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AFAICS you're not allowing your clients to do DNS queries... see below

On Thu, Jul 29, 1999 at 03:16:38PM -0500, David B. Aas wrote:
> Whoops!
> 
> I forgot to include my rules. Sorry for the extra email.
> 
> # Setup system for firewall service.
> # $Id: rc.firewall,v 1.19.2.1 1999/02/10 18:08:38 jkh Exp $
> # Customized by Dave Aas 1999/07/20
> 
> # Suck in the configuration variables.
> if [ -f /etc/defaults/rc.conf ]; then
> 	. /etc/defaults/rc.conf
> elif [ -f /etc/rc.conf ]; then
> 	. /etc/rc.conf
> fi
> 
> # Flush out the list before we begin.
> ipfw -f flush
> 
> # Divert internal ip addresses
> ipfw add 100 divert natd all from any to any via ${natd_interface}
> 
> # Allow all outbound traffic
> ipfw add 150 allow all from any to any out
> 
> # Only in rare cases do you want to change these rules
> ipfw add 200 pass all from any to any via lo0
> ipfw add 300 deny all from any to 127.0.0.0/8
> 
> # Stop spoofing
> ipfw add 400 deny all from ${inet}:${imask} to any in via ${oif}
> ipfw add 500 deny all from ${onet}:${omask} to any in via ${iif}
> 
> # Allow TCP through if setup succeeded
> ipfw add 600 pass tcp from any to any established
> 
> # Allow setup of incoming email
> ipfw add 700 pass tcp from any to ${oip} 25 setup
> ipfw add 710 allow tcp from any to any 110 setup
> 
> # Allow access to our DNS
> ipfw add 800 pass tcp from any to ${oip} 53 setup

this says let my machine talk to DNS servers on the internet for
zone transfers (TCP)

> 
> # Allow access to our WWW
> ipfw add 900 pass tcp from any to ${oip} 80 setup
> 
> # Other webserver traffic
> ipfw add 910 allow tcp from any to ${oip} 80 in via ${oif}
> ipfw add 920 allow tcp from any to ${oip} 3128 in via ${oif}
> 
> # Allow setup of outgoing TCP connections only
> ipfw add 1000 allow tcp from ${oip}:${omask} to any setup
> ipfw add 1100 allow tcp from ${iip}:${imask} to any setup
> 
> # Allow maintenance from CI
> ipfw add 1200 allow tcp from ${maintip} to ${oip} 21 setup
> ipfw add 1300 allow tcp from ${maintip} to ${oip} 23 setup
> 
> # Allow DNS queries out in the world
> ipfw add 1400 pass udp from any 53 to ${oip}
> ipfw add 1500 pass udp from ${oip} to any 53

this says allow my server to ask DNS queries from the internet.
You should add a rule saying "let my clients do DNS queries"
I would change those previous two rules for

ipfw add 1400 pass udp from any 53 to any
ipfw add 1500 pass udp from any to any 53

regards,

-Oscar

-- 
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