Follow Techotopia on Twitter

On-line Guides
All Guides
eBook Store
iOS / Android
Linux for Beginners
Office Productivity
Linux Installation
Linux Security
Linux Utilities
Linux Virtualization
Linux Kernel
System/Network Admin
Scripting Languages
Development Tools
Web Development
GUI Toolkits/Desktop
Mail Systems
Eclipse Documentation

How To Guides
General System Admin
Linux Security
Linux Filesystems
Web Servers
Graphics & Desktop
PC Hardware
Problem Solutions
Privacy Policy




NOTE: CentOS Enterprise Linux is built from the Red Hat Enterprise Linux source code. Other than logo and name changes CentOS Enterprise Linux is compatible with the equivalent Red Hat version. This document applies equally to both Red Hat and CentOS Enterprise Linux.

4.6. Personal Firewalls

Once the necessary network services are configured, it is important to implement a firewall.

Firewalls prevent network packets from accessing the system's network interface. If a request is made to a port that is blocked by a firewall, the request is ignored. If a service is listening on one of these blocked ports, it does not receive the packets and is effectively disabled. For this reason, care should be taken when configuring a firewall to block access to ports not in use, while not blocking access to ports used by configured services.

For most users, the best tool for configuring a simple firewall is the straight-forward, graphical firewall configuration tool which ships with Red Hat Enterprise Linux: the Security Level Configuration Tool (system-config-securitylevel). This tool creates broad iptables rules for a general-purpose firewall using a control panel interface.

For more information about using this application and the options it offers, refer to the chapter titled Basic Firewall Configuration in the Red Hat Enterprise Linux System Administration Guide.

For advanced users and server administrators, manually configuring a firewall with iptables is likely the best option. Refer to Chapter 7 Firewalls for more information. For a comprehensive guide to the iptables command, consult the chapter titled iptables in the Red Hat Enterprise Linux Reference Guide.

  Published under the terms of the GNU General Public License Design by Interspire