Hello Everyone

By reading New Riders “Linux Firewalls” by Robert L. Ziegler I’m just starting to study iptables.  I have a stand-alone firewall offline and off the local network running RHL 7.3 with Kernel 2.4.18-3 and iptables 1.2.5.

I’ve just started writing the script to allow DNS Loopkups as a client with the following:

if [ "$CONNECTION_TRACKING" = "1" ]; then

    iptables -A OUTPUT -o $INTERNET -p udp \

             -s $IPADDR --sport $UNPRIVPORTS \

             -d $NAMESERVER --dport 53 \

             -m state --state NEW -j ACCEPT

fi

iptables -A OUTPUT -o $INTERNET -p udp \

         -s $IPADDR --sport $UNPRIVPORTS \

         -d $NAMESERVER --dport 53 -j ACCEPT

iptables -A INPUT  -i $INTERNET -p udp \

         -s $NAMESERVER --sport 53 \

         -d $IPADDR --dport $UNPRIVPORTS -j ACCEPT

When I execute the script with sh /etc/rc.d/rc.firewalls I receive Bad argument `53' for every instance of either  --dport 53 or --sport 53.  I’ve also tried --destination-port and --source-port with out any success.