Customize a more friendly iptables firewall
Original security
[root@localhost~]# vi /etc/iptables_settings.sh
#################################################################
#!/ bin/sh -e
#----------------------------------------------------------
# iptables settings
#----------------------------------------------------------
#Connection IP address
SSH_IP1="192.168.1.0/24"
SSH_IP2="192.168.2.0/24"
SNMP_IP1="10.10.1.1"
SNMP_IP2="10.10.2.1"
#----------------------Standard part---------------------------
# Stop iptables service first
#service iptables stop
/sbin/iptables -F
/sbin/iptables -X
/sbin/iptables -Z
# Inital chains default policy
/sbin/iptables -F -t filter
/sbin/iptables -P INPUT DROP
/sbin/iptables -P OUTPUT ACCEPT
# Enable Native Network Transfer
/sbin/iptables -A INPUT -i lo -j ACCEPT
# Accept Established Connections
/sbin/iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
# ICMP Control
/sbin/iptables -A INPUT -p icmp -m limit --limit 1/s --limit-burst 10 -j ACCEPT
# SSH Service
/sbin/iptables -A INPUT -s $SSH_IP1 -p tcp --dport 22 -j ACCEPT
/sbin/iptables -A INPUT -s $SSH_IP2 -p tcp --dport 22 -j ACCEPT
# SNMP Service
/sbin/iptables -A INPUT -s $SNMP_IP1 -p udp --dport 161 -j ACCEPT
/sbin/iptables -A INPUT -s $SNMP_IP2 -p udp --dport 161 -j ACCEPT
#-----------------------Custom part-----------------------
# Name Service
/sbin/iptables -A INPUT -p tcp --dport 53 -j ACCEPT
/sbin/iptables -A INPUT -p udp --dport 53 -j ACCEPT
Add custom content here
#deny all Service
/sbin/iptables -A INPUT -j REJECT --reject-with icmp-host-prohibited
/sbin/iptables -A FORWARD -j REJECT --reject-with icmp-host-prohibited
#################################################################
[root@localhost~]# chmod +x /etc/iptables_settings.sh
[root@localhost~]# echo "/etc/iptables_settings.sh">>/etc/rc.local
[root@localhost~]# chkconfig iptables off
[root@localhost~]# service iptables stop
[root@localhost~]# /etc/iptables_settings.sh
[root@localhost~]# iptables -L
