How can i debug my iptables script? #!/bin/sh # # The location of the IPTables binary file on your system. IPT="/sbin/iptables" # The Internet interface. For ADSL or Dialup users, this should be "ppp0". # For a cable modem connection, this will probably be "eth0". INT="ppp0" # Out with the old stuff. $IPT -F $IPT -F INPUT $IPT -F OUTPUT $IPT -F FORWARD $IPT -F -t mangle $IPT -F -t nat $IPT -X # These will setup our policies. $IPT -P INPUT DROP $IPT -P OUTPUT ACCEPT $IPT -P FORWARD ACCEPT # Use this for NAT or IP Masquerading. echo 1 > /proc/sys/net/ipv4/ip_forward $IPT -t nat -A POSTROUTING -o $INT -j MASQUERADE # This rule protects your fowarding rule. $IPT -A FORWARD -i $INT -m state --state NEW,INVALID -j DROP # Port forwarding looks like this. #$IPT -t nat -A PREROUTING -i $INT -p tcp --dport 25 -j DNAT --to 192.168.0.50 #$IPT -t nat -A PREROUTING -i $INT -p tcp --dport 53 -j DNAT --to 192.168.0.50 #$IPT -t nat -A PREROUTING -i $INT -p udp --dport 53 -j DNAT --to 192.168.0.50 # These two redirect a block of ports, in both udp and tcp. #$IPT -t nat -A PREROUTING -i $INT -p tcp --dport 2300:2400 -j DNAT --to 192.168.0.50 #$IPT -t nat -A PREROUTING -i $INT -p udp --dport 2300:2400 -j DNAT --to 192.168.0.50 # This rule will accept connections from local machines. $IPT -A INPUT -i lo -j ACCEPT $IPT -A INPUT -s 192.168.0.0/24 -d 0/0 -p all -j ACCEPT # Drop bad packets. $IPT -A INPUT -p tcp --tcp-flags ALL FIN,URG,PSH -j DROP $IPT -A INPUT -p tcp --tcp-flags ALL ALL -j DROP $IPT -A INPUT -p tcp --tcp-flags ALL SYN,RST,ACK,FIN,URG -j DROP $IPT -A INPUT -p tcp --tcp-flags ALL NONE -j DROP $IPT -A INPUT -p tcp --tcp-flags SYN,RST SYN,RST -j DROP $IPT -A INPUT -p tcp --tcp-flags SYN,FIN SYN,FIN -j DROP # Drop icmp, but only after letting certain types through. $IPT -A INPUT -p icmp --icmp-type 0 -j ACCEPT $IPT -A INPUT -p icmp --icmp-type 3 -j ACCEPT $IPT -A INPUT -p icmp --icmp-type 11 -j ACCEPT $IPT -A INPUT -p icmp --icmp-type 8 -m limit --limit 1/second -j ACCEPT $IPT -A INPUT -p icmp -j DROP ===== EliteSyntax www.linuxnewbie.org __________________________________ Do you Yahoo!? SBC Yahoo! DSL - Now only $29.95 per month! http://sbc.yahoo.com
