Configure firewall¶

Requirements¶

To configure Firewall you will need the following:

• a installed and supported operating system (e.g. CentOS 6.x)
• root-access

Preliminary Note¶

It is good practice to open only those ports needed.

Configure¶

system-config-firewall-tui

Main-Page, this is the place to enable/disable the firewall, via Customize you can alter the configuration

The Trusted Service page allows to open common ports for incoming connections, e.g. 22 SSH

Ports not being listed in the Trusted Services might be opened here, e.g. 5432 PostgreSQL

If you trust all participants on a specific network-interface, you can mark them here:

Same goes with Masquerading

Portforwarding usually goes with Masquerading

If you want to ignore certain ICMP types, e.g. Ping, this is the place

Anything not being covered in the previous screens might be entered here

After doing some changes to the configuration you will be asked to confirm the changes.

It is always worth double check the configuration by

service iptables status

or

cat /etc/sysconfig/system-config-firewall

or

cat /etc/sysconfig/iptables