Linux firewall plus white list __linux

Install yum install iptables-services on Linux systems

Then Vi/etc/sysconfig/iptables

# generated by Iptables-save v1.4.7 on Sun Aug 28 12:14:02 2016
*filter
: INPUT ACCEPT [0:0]
: FORWARD ACCEPT [0:0]
: OUTPUT ACCEPT [0:0]


-N Whitelist
-A whitelist-s 8.8.8.8-j ACCEPT
-A whitelist-s x.x.x.x-j ACCEPT

-A whitelist-s x.x.x.x-j ACCEPT

-A whitelist-s x.x.x.x-j ACCEPT

-A whitelist-s x.x.x.x-j ACCEPT

-A whitelist-s x.x.x.x-j ACCEPT
-A input-m state--state related,established-j ACCEPT
-A input-p icmp-j ACCEPT
-A input-i lo-j ACCEPT
-A input-m state--state new-m tcp-p TCP--dport 22-j Whitelist
-A input-m state--state new-m tcp-p TCP--dport 80-j Whitelist
-A input-m state--state new-m tcp-p TCP--dport 443-j Whitelist
-A input-m state--state new-m tcp-p TCP--dport 25-j Whitelist
-A input-j REJECT--reject-with icmp-host-prohibited
-A forward-j REJECT--reject-with icmp-host-prohibited

COMMIT

Top is the list of IP lists of whitelist

Below are some ports that are open for the contents of the whitelist

Write the accept on the top.

Write the contents of the reject down below.

So the white list of IP can access our restricted ports and services, and not in the whitelist IP will be rejected.

-A input-m state--state new-m tcp-p TCP--dport 22-j Whitelist This is for the white list of ports open, that is, only white list of IP can access through this port.

-A input-m State--state new-m tcp-p TCP--dport 22-j This is all white open, that is, any machine can access through this port.