Dear all, I have the iptables ruleset attached below. Using the ruleset, I could not access the LAN_IP and INET_IP via ping command. But ping to 127.0.0.1 was no problem
Any help would be very appreciated best regards -miral-
# #This script based on Oskar Andreasson (from iptables tutorial 1.1.5) # # #Define parameter # LAN_IP_RANGE="10.x.x.x/255.255.255.0" LAN_IP="10.x.x.x/32" LAN_BCAST_ADRESS="10.x.x.x/32" LAN_IFACE="eth0" LO_IP="127.0.0.1/32" LO_IFACE="lo" INET_IP="20x.x.x.x/32" INET_IFACE="eth1" IPTABLES="/usr/local/sbin/iptables" # #Load the needed ip tables modules # /sbin/depmod -a /sbin/modprobe ip_tables /sbin/modprobe ip_conntrack /sbin/modprobe ip_conntrack_ftp /sbin/modprobe ip_conntrack_irc /sbin/modprobe ip_conntrack_h323 /sbin/modprobe ip_conntrack_talk /sbin/modprobe ip_nat_ftp /sbin/modprobe ip_nat_irc ports=6667,6668,6669,7000 /sbin/modprobe ip_nat_h323 /sbin/modprobe ip_nat_talk /sbin/modprobe ipt_LOG /sbin/modprobe ipt_MASQUERADE /sbin/modprobe ipt_REDIRECT # #Enable ip forward # echo "1" > /proc/sys/net/ipv4/ip_forward # # Enable simple IP Forwarding and Network Address Translation # $IPTABLES -t nat -A POSTROUTING -s $LAN_IP_RANGE -o $INET_IFACE -j MASQUERADE # # Bad TCP packets we don't want # $IPTABLES -A FORWARD -p tcp ! --syn -m state --state NEW -j LOG --log-prefix "New not syn:" $IPTABLES -A FORWARD -p tcp ! --syn -m state --state NEW -j DROP # # Accept the packets we actually want to forward # $IPTABLES -A FORWARD -i $LAN_IFACE -j ACCEPT $IPTABLES -A FORWARD -i ppp+ -j ACCEPT $IPTABLES -A FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT $IPTABLES -A FORWARD -m limit --limit 3/minute --limit-burst 3 -j LOG --log-level DEBUG --log-prefix "IPT FORWARD packet died:" # # Set default policies for the INPUT, FORWARD and OUTPUT chains # $IPTABLES -P INPUT DROP $IPTABLES -P OUTPUT DROP $IPTABLES -P FORWARD DROP # # Create separate chains for ICMP, TCP and UDP to traverse # $IPTABLES -N icmp_packets $IPTABLES -N tcp_packets $IPTABLES -N udpincoming_packets # # The allowed chain for TCP connections # $IPTABLES -N allowed $IPTABLES -A allowed -p TCP --syn -j ACCEPT $IPTABLES -A allowed -p TCP -m state --state ESTABLISHED,RELATED -j ACCEPT $IPTABLES -A allowed -p TCP -j DROP # # ICMP rules # $IPTABLES -A icmp_packets -p ICMP -s 0/0 --icmp-type 0 -j ACCEPT $IPTABLES -A icmp_packets -p ICMP -s 0/0 --icmp-type 3 -j ACCEPT $IPTABLES -A icmp_packets -p ICMP -s 0/0 --icmp-type 5 -j ACCEPT $IPTABLES -A icmp_packets -p ICMP -s 0/0 --icmp-type 11 -j ACCEPT # # TCP rules # #$IPTABLES -A tcp_packets -p TCP -s 0/0 --dport 21 -j allowed #$IPTABLES -A tcp_packets -p TCP -s 0/0 --dport 22 -j allowed #$IPTABLES -A tcp_packets -p TCP -s 0/0 --dport 80 -j allowed $IPTABLES -A tcp_packets -p TCP -s 0/0 --dport 113 -j allowed # # UDP ports # $IPTABLES -A udpincoming_packets -p UDP -s 0/0 --source-port 53 -j ACCEPT $IPTABLES -A udpincoming_packets -p UDP -s 0/0 --source-port 123 -j ACCEPT $IPTABLES -A udpincoming_packets -p UDP -s 0/0 --source-port 2074 -j ACCEPT $IPTABLES -A udpincoming_packets -p UDP -s 0/0 --source-port 4000 -j ACCEPT # # PREROUTING chain. # # Do some checks for obviously spoofed IP's # $IPTABLES -t nat -A PREROUTING -i $INET_IFACE -s 192.168.0.0/16 -j DROP $IPTABLES -t nat -A PREROUTING -i $INET_IFACE -s 10.0.0.0/8 -j DROP $IPTABLES -t nat -A PREROUTING -i $INET_IFACE -s 172.16.0.0/12 -j DROP # # INPUT chain # # Take care of bad TCP packets that we don't want # $IPTABLES -A INPUT -p tcp ! --syn -m state --state NEW -j LOG --log-prefix "New not syn:" $IPTABLES -A INPUT -p tcp ! --syn -m state --state NEW -j DROP # # Rules for incoming packets from the internet # $IPTABLES -A INPUT -p ICMP -i $INET_IFACE -j icmp_packets $IPTABLES -A INPUT -p TCP -i $INET_IFACE -j tcp_packets $IPTABLES -A INPUT -p UDP -i $INET_IFACE -j udpincoming_packets # # Rules for special networks not part of the Internet # #$IPTABLES -A INPUT -p ALL -i $LAN_IFACE -d $LAN_BCAST_ADRESS -j ACCEPT $IPTABLES -A INPUT -p ALL -i $LO_IFACE -d $LO_IP -j ACCEPT $IPTABLES -A INPUT -p ALL -i $LAN_IFACE -d $LAN_IP -j ACCEPT $IPTABLES -A INPUT -p ALL -i ppp+ -j ACCEPT $IPTABLES -A INPUT -p ALL -d $INET_IP -m state --state ESTABLISHED,RELATED -j ACCEPT $IPTABLES -A INPUT -m limit --limit 3/minute --limit-burst 3 -j LOG --log-level DEBUG --log-prefix "IPT INPUT packet died: " # # OUTPUT chain # $IPTABLES -A OUTPUT -p tcp ! --syn -m state --state NEW -j LOG --log-prefix "New not syn:" $IPTABLES -A OUTPUT -p tcp ! --syn -m state --state NEW -j DROP $IPTABLES -A OUTPUT -p ALL -s $LO_IP -j ACCEPT $IPTABLES -A OUTPUT -p ALL -s $LAN_IP -j ACCEPT $IPTABLES -A OUTPUT -p ALL -s $INET_IP -j ACCEPT $IPTABLES -A OUTPUT -p ALL -o $INET_IFACE -j ACCEPT $IPTABLES -A OUTPUT -m limit --limit 3/minute --limit-burst 3 -j LOG --log-level DEBUG --log-prefix "IPT OUTPUT packet died: "
