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Date:      Thu, 25 Apr 2002 14:32:22 -0400
From:      "Carolyn Longfoot" <c_longfoot@hotmail.com>
To:        freebsd-questions@freebsd.org
Subject:   rc.firewall problems
Message-ID:  <F139xSLRKybIFycsa1N0000c049@hotmail.com>
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I have the following setup and I cannot figure out why only the firewall 
server itself, but nobody else on the network can get out. I compared the 
entries with all documentation I could get my hands on (Complete FreeBSD, 
Handbook...) but found no real differences.

If anybody could point me to what I'm missing I'd appreciate it. I am 
running NAT and to get anything to work I added the rows marked with === 
(not marked in the actual file of course). That feels pretty wrong and I'm 
especially puzzled why BOTH are needed, i can see that 'sh rc.firewall' 
executed the nat rule further down so why would the first one make a 
difference?

Cheers,

Caro

	# set these to your outside interface network and netmask and ip
	oif="rl0"
	onet="1.1.1.0"
	omask="255.255.255.252"
	oip="1.1.1.1"

	# set these to your inside interface network and netmask and ip
	iif="rl1"
	inet="10.0.0.0"
	imask="255.255.255.0"
	iip="10.0.0.1"

===	${fwcmd} add divert natd all from any to any via ${oif}
===     ${fwcmd} add pass all from any to any

	# Stop spoofing
	${fwcmd} add deny all from ${inet}:${imask} to any in via ${oif}
	${fwcmd} add deny all from ${onet}:${omask} to any in via ${iif}

	# Stop RFC1918 nets on the outside interface
	${fwcmd} add deny all from any to 10.0.0.0/8 via ${oif}
	${fwcmd} add deny all from any to 172.16.0.0/12 via ${oif}
	${fwcmd} add deny all from any to 192.168.0.0/16 via ${oif}

	# Stop draft-manning-dsua-03.txt (1 May 2000) nets (includes RESERVED-1,
	# DHCP auto-configuration, NET-TEST, MULTICAST (class D), and class E)
	# on the outside interface
	${fwcmd} add deny all from any to 0.0.0.0/8 via ${oif}
	${fwcmd} add deny all from any to 169.254.0.0/16 via ${oif}
	${fwcmd} add deny all from any to 192.0.2.0/24 via ${oif}
	${fwcmd} add deny all from any to 224.0.0.0/4 via ${oif}
	${fwcmd} add deny all from any to 240.0.0.0/4 via ${oif}

	# Network Address Translation.  This rule is placed here deliberately
	# so that it does not interfere with the surrounding address-checking
	# rules.  If for example one of your internal LAN machines had its IP
	# address set to 192.0.2.1 then an incoming packet for it after being
	# translated by natd(8) would match the `deny' rule above.  Similarly
	# an outgoing packet originated from it before being translated would
	# match the `deny' rule below.
	case ${natd_enable} in
	[Yy][Ee][Ss])
		if [ -n "${natd_interface}" ]; then
			${fwcmd} add divert natd all from any to any via ${natd_interface}
		fi
		;;
	esac

	# Stop RFC1918 nets on the outside interface
	${fwcmd} add deny all from 10.0.0.0/8 to any via ${oif}
	${fwcmd} add deny all from 172.16.0.0/12 to any via ${oif}
	${fwcmd} add deny all from 192.168.0.0/16 to any via ${oif}

	# Stop draft-manning-dsua-03.txt (1 May 2000) nets (includes RESERVED-1,
	# DHCP auto-configuration, NET-TEST, MULTICAST (class D), and class E)
	# on the outside interface
	${fwcmd} add deny all from 0.0.0.0/8 to any via ${oif}
	${fwcmd} add deny all from 169.254.0.0/16 to any via ${oif}
	${fwcmd} add deny all from 192.0.2.0/24 to any via ${oif}
	${fwcmd} add deny all from 224.0.0.0/4 to any via ${oif}
	${fwcmd} add deny all from 240.0.0.0/4 to any via ${oif}

	${fwcmd} add pass all from any to any via ${iif}
	${fwcmd} add pass all from ${onet}:${omask} to any out via ${oif}

	# Allow TCP through if setup succeeded
	${fwcmd} add pass tcp from any to any established

	# Allow IP fragments to pass through
	${fwcmd} add pass all from any to any frag

	# Allow setup of incoming email
	${fwcmd} add pass tcp from any to ${oip} 25 setup

	# Allow access to our DNS
	${fwcmd} add pass tcp from any to ${oip} 53 setup
	${fwcmd} add pass udp from any to ${oip} 53
	${fwcmd} add pass udp from ${oip} 53 to any

	# Allow access to our WWW
	${fwcmd} add pass tcp from any to ${oip} 80 setup

	# Reject&Log all setup of incoming connections from the outside
	${fwcmd} add deny log tcp from any to any in via ${oif} setup

	# Allow setup of any other TCP connection
	${fwcmd} add pass tcp from any to any setup

	# Allow DNS queries out in the world
	${fwcmd} add pass udp from any 53 to ${oip}
	${fwcmd} add pass udp from ${oip} to any 53

	# Allow NTP queries out in the world
	${fwcmd} add pass udp from any 123 to ${oip}
	${fwcmd} add pass udp from ${oip} to any 123

	# Everything else is denied by default, unless the
	# IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel
	# config file.
	;;


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