Set a firewall whitelist in Linux (RHEL 6 and CentOS 7)

Set a firewall whitelist in Linux (RHEL 6 and CentOS 7)

Go to the Linux Command Line and edit the firewall rule configuration file iptables.
Vi/etc/sysconfig/iptables

The following is an example of whitelist settings:

# Firewall configuration written by system-config-securitylevel# Manual customization of this file is not recommended.*filter:INPUT ACCEPT [0:0]:FORWARD ACCEPT [0:0]:OUTPUT ACCEPT [0:0]:RH-Firewall-1-INPUT - [0:0]-N whitelist-A whitelist -s 10.202.106.1 -j ACCEPT-A whitelist -s 10.202.106.2 -j ACCEPT-A whitelist -s 10.202.106.3 -j ACCEPT-A whitelist -s 10.202.106.4 -j ACCEPT-A whitelist -s 10.202.106.5 -j ACCEPT-A whitelist -s 10.202.106.6 -j ACCEPT-A whitelist -s 10.202.106.7 -j ACCEPT-A INPUT -j RH-Firewall-1-INPUT-A FORWARD -j RH-Firewall-1-INPUT-A RH-Firewall-1-INPUT -i lo -j ACCEPT-A RH-Firewall-1-INPUT -p icmp --icmp-type any -j ACCEPT-A RH-Firewall-1-INPUT -p 50 -j ACCEPT-A RH-Firewall-1-INPUT -p 51 -j ACCEPT-A RH-Firewall-1-INPUT -p udp --dport 5353 -d 224.0.0.251 -j ACCEPT-A RH-Firewall-1-INPUT -p udp -m udp --dport 631 -j ACCEPT-A RH-Firewall-1-INPUT -p tcp -m tcp --dport 631 -j ACCEPT-A RH-Firewall-1-INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 4750 -j ACCEPT-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 3306 -j whitelist-A RH-Firewall-1-INPUT -j REJECT --reject-with icmp-host-prohibitedCOMMIT

The whitelist settings are as follows:

-N whitelist-A whitelist -s 10.202.106.1 -j ACCEPT-A whitelist -s 10.202.106.2 -j ACCEPT-A whitelist -s 10.202.106.3 -j ACCEPT-A whitelist -s 10.202.106.4 -j ACCEPT-A whitelist -s 10.202.106.5 -j ACCEPT-A whitelist -s 10.202.106.6 -j ACCEPT-A whitelist -s 10.202.106.7 -j ACCEPT

Use the j parameter to specify the whitelist rules:

-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 3306 -j whitelist