Iptables Tutorial 1.2.2

ОглавлениеДобавить в закладки К обложке

#echo "1" > /proc/sys/net/ipv4/conf/all/proxy_arp

#echo "1" > /proc/sys/net/ipv4/ip_dynaddr

###########################################################################

#

# 4. rules set up.

#

######

# 4.1 Filter table

#

#

# 4.1.1 Set policies

#

$IPTABLES -P INPUT DROP

$IPTABLES -P OUTPUT DROP

$IPTABLES -P FORWARD DROP

#

# 4.1.2 Create userspecified chains

#

#

# Create chain for bad tcp packets

#

$IPTABLES -N bad_tcp_packets

#

# Create separate chains for ICMP, TCP and UDP to traverse

#

$IPTABLES -N allowed

$IPTABLES -N tcp_packets

$IPTABLES -N udp_packets

$IPTABLES -N icmp_packets

#

# 4.1.3 Create content in userspecified chains

#

#

# bad_tcp_packets chain

#

$IPTABLES -A bad_tcp_packets -p tcp --tcp-flags SYN,ACK SYN,ACK \

-m state --state NEW -j REJECT --reject-with tcp-reset

$IPTABLES -A bad_tcp_packets -p tcp ! --syn -m state --state NEW -j LOG \

--log-prefix "New not syn:"

$IPTABLES -A bad_tcp_packets -p tcp ! --syn -m state --state NEW -j DROP

#

# allowed chain

#

$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

#

# 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 udp_packets -p UDP -s 0/0 --source-port 53 -j ACCEPT

if [ $DHCP == "yes" ] ; then

$IPTABLES -A udp_packets -p UDP -s $DHCP_SERVER --sport 67 \

--dport 68 -j ACCEPT

fi

#$IPTABLES -A udp_packets -p UDP -s 0/0 --source-port 53 -j ACCEPT

#$IPTABLES -A udp_packets -p UDP -s 0/0 --source-port 123 -j ACCEPT

#$IPTABLES -A udp_packets -p UDP -s 0/0 --source-port 2074 -j ACCEPT

#$IPTABLES -A udp_packets -p UDP -s 0/0 --source-port 4000 -j ACCEPT

#

# In Microsoft Networks you will be swamped by broadcasts. These lines

# will prevent them from showing up in the logs.

#

#$IPTABLES -A udp_packets -p UDP -i $INET_IFACE \

#--destination-port 135:139 -j DROP

#

# If we get DHCP requests from the Outside of our network, our logs will

# be swamped as well. This rule will block them from getting logged.

#

#$IPTABLES -A udp_packets -p UDP -i $INET_IFACE -d 255.255.255.255 \

#--destination-port 67:68 -j DROP

#

# ICMP rules

#

$IPTABLES -A icmp_packets -p ICMP -s 0/0 --icmp-type 8 -j ACCEPT

$IPTABLES -A icmp_packets -p ICMP -s 0/0 --icmp-type 11 -j ACCEPT

#

# 4.1.4 INPUT chain

#

#

# Bad TCP packets we don't want.

#

$IPTABLES -A INPUT -p tcp -j bad_tcp_packets

#

# Rules for special networks not part of the Internet

#

$IPTABLES -A INPUT -p ALL -i $LAN_IFACE -s $LAN_IP_RANGE -j ACCEPT

$IPTABLES -A INPUT -p ALL -i $LO_IFACE -j ACCEPT

#

# Special rule for DHCP requests from LAN, which are not caught properly

# otherwise.

#

$IPTABLES -A INPUT -p UDP -i $LAN_IFACE --dport 67 --sport 68 -j ACCEPT

#

# Rules for incoming packets from the internet.

#

$IPTABLES -A INPUT -p ALL -i $INET_IFACE -m state --state ESTABLISHED,RELATED \

-j ACCEPT

$IPTABLES -A INPUT -p TCP -i $INET_IFACE -j tcp_packets

$IPTABLES -A INPUT -p UDP -i $INET_IFACE -j udp_packets

$IPTABLES -A INPUT -p ICMP -i $INET_IFACE -j icmp_packets

#

# If you have a Microsoft Network on the outside of your firewall, you may

# also get flooded by Multicasts. We drop them so we do not get flooded by


-= 298 =-
Регистрация.
Забыли пароль?
Логин
Пароль
Запомнить меня