Shorewall

Shorewall is a gateway/firewall configuration tool for GNU/Linux.

Firewall OS: CentOS 7 - 64bits  and Install showwall 

Our Diagram: 

• Installations:
• Install repo

yum install epel-release

• Install Shorewall

yum install shorewall -y

• SHOREWALL.CONF

vi /etc/shorewall/shorewall.conf

STARTUP_ENABLED=Yes

• ZONE

vim /etc/shorewall/zones

fw      firewall

wan     ipv4

lan     ipv4

• INTERFACE

vim /etc/shorewall/interfaces

wan     eno16777736    detect  routefilter,tcpflags,logmartians,nosmurfs

lan     eno33554984    detect  tcpflags

• POLICY

vim /etc/shorewall/policy

$FW              wan            ACCEPT

lan             $FW             ACCEPT

lan             wan             ACCEPT

wan             all             DROP            info

# THE FOLLOWING POLICY MUST BE LAST

all             all             REJECT          info

• RULES

vim /etc/shorewall/rules

If you want to allow ping from internet add this in file rules.

Ping(ACCEPT)    wan     $FW

• MASQ

vim /etc/shorewall/masq

eno16777736     172.16.5.0/24

• Verify Settings and restart

shorewall check

shorewall restart

Done, All your network LAN 172.16.5.0/24 should be go to internet via firewall.