Setting up a firewall whitelist under Linux (RHEL 6 and CentOS 7)

Enter the Linux command line and edit the firewall rules configuration file iptables vi /etc/sysconfig/iptables

The following is an example of a whitelist setting:
? 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 <code class="hljs haml"># Firewall configuration written by system-config-securitylevel # Manual customization of this file is not recommended. *filt Er :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-prohibited COMMIT</code>

The part in which the whitelist is set is:
? 1 2 3 4 5 6 7 8 <code class="hljs haml"><code class="hljs lasso">-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</code></code>

Use whitelist rules with j parameter specification:
? 1 <code class= "hljs haml"><code class="hljs lasso"><code class="hljs lasso">-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 3306 -j whitelist</code></code></code>