+dnsserver inbound
+
+## IPv6 6-in-4 tunnel.
+run iptables -A inbound -j ACCEPT \
+ -p $proto_ipv6 -s 216.66.80.26
+
+## Permitted special forwarding.
+makeset fwd-allow-http nethash || :
+iptables -A fwd-spec-nofrag -j ACCEPT \
+ -m set --match-set fwd-allow-http dst \
+ -p tcp --destination-port $port_http \
+ -m mark --mark $to_untrusted/$MASK_TO
+iptables -A fwd-spec-nofrag -j ACCEPT \
+ -m set --match-set fwd-allow-http src \
+ -p tcp --destination-port $port_http \
+ -m mark --mark $from_untrusted/$MASK_FROM \
+ -m state --state ESTABLISHED
+
+## NAT for RFC1918 addresses.
+for i in PREROUTING OUTPUT POSTROUTING; do
+ run iptables -t nat -P $i ACCEPT 2>/dev/null || :
+ run iptables -t nat -F $i 2>/dev/null || :
+done
+run iptables -t nat -F
+run iptables -t nat -X
+
+run iptables -t nat -N outbound
+run iptables -t nat -A outbound -j RETURN ! -o ppp0
+run iptables -t nat -A outbound -j RETURN ! -s 172.29.198.0/23
+run iptables -t nat -A outbound -j RETURN -d 62.49.204.144/28
+run iptables -t nat -A outbound -j RETURN -d 172.29.198.0/23
+run iptables -t nat -A outbound -j SNAT --to-source 62.49.204.158
+run iptables -t nat -A POSTROUTING -j outbound
+
+## TCP MSS clamping to help given Demon's sluggish approach to fragmentation-
+## needed errors.
+run ip46tables -t mangle -A FORWARD -o ppp0 -p tcp --tcp-flags SYN,RST SYN \
+ -j TCPMSS --clamp-mss-to-pmtu
+
+## Set up NAT protocol helpers. In particular, SIP needs some special
+## twiddling.
+run modprobe nf_conntrack_sip \
+ ports=5060 \
+ sip_direct_signalling=0 \
+ sip_direct_media=0
+for p in ftp sip h323; do
+ run modprobe nf_nat_$p
+done
+
+## Forbid anything complicated to the NAT address. Be sure to allow ident,
+## though.
+run iptables -A INPUT -d 62.49.204.158 -p tcp -j ACCEPT \
+ -m multiport --destination-ports=113
+run iptables -A INPUT -d 62.49.204.158 ! -p icmp -j REJECT