Iptables simple Firewall configuration
Firewall with camouflage enabled.
[root@server ~]# vi /etc/sysconfig/iptables*filter:INPUT DROP [0:0]:FORWARD DROP [0:0]:OUTPUT DROP [0:0]-A INPUT -m state --state INVALID -j DROP-A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT-A INPUT -p tcp -m tcp --dport 22 --syn -m state --state NEW -j ACCEPT-A INPUT -p tcp -m tcp --dport 80 --syn -m state --state NEW -j ACCEPT-A INPUT -p icmp -m icmp --icmp-type 0 -j ACCEPT-A INPUT -p icmp -m icmp --icmp-type 8 -j ACCEPT-A INPUT -i lo -j ACCEPT-A INPUT -s 0.0.0.0/32 -d 255.255.255.255/32 -i wlp2s0 -j ACCEPT-A INPUT -s 172.16.0.0/16 -i wlp2s0 -j ACCEPT-A FORWARD -m state --state INVALID -j DROP-A FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT-A FORWARD -p tcp -m tcp --syn -m state --state NEW -j ACCEPT-A FORWARD -p udp -m state --state NEW -j ACCEPT-A FORWARD -p icmp -m icmp --icmp-type 0 -j ACCEPT-A FORWARD -p icmp -m icmp --icmp-type 8 -j ACCEPT-A FORWARD -o lo -j ACCEPT-A FORWARD -s 172.16.0.0/16 -i wlp2s0 -j ACCEPT-A OUTPUT -m state --state INVALID -j DROP-A OUTPUT -m state --state RELATED,ESTABLISHED -j ACCEPT-A OUTPUT -p tcp -m tcp --syn -m state --state NEW -j ACCEPT-A OUTPUT -p udp -m state --state NEW -j ACCEPT-A OUTPUT -p icmp -m icmp --icmp-type 0 -j ACCEPT-A OUTPUT -p icmp -m icmp --icmp-type 8 -j ACCEPT-A OUTPUT -o lo -j ACCEPT-A OUTPUT -d 172.16.0.0/16 -o wlp2s0 -j ACCEPTCOMMIT*nat:PREROUTING ACCEPT [0:0]:INPUT ACCEPT [0:0]:OUTPUT ACCEPT [0:0]:POSTROUTING ACCEPT [0:0]-A POSTROUTING -s 172.16.0.0/24 -o enp3s0 -j MASQUERADECOMMIT