Securing Linux systems with host-based firewalls implemented with Linux iptables
The goal of this article is to provide the reader with a template for constructing a host-based firewall that provides a useful layer of protection against the risks of exposing a system to internal and/or external users. Additionally, the reader can gain an understanding of construction methods for host-based firewalls in general and Linux-based firewalls in particular.
This article is targeted for use with RedHat Advanced Server 2.1 and SuSE Enterprise Server 8, but most of the material applies to distributions based on Linux kernel version 2.4 and newer.
We assume that the reader is capable of creating basic Bourne shell scripts and can perform basic system administration tasks.
By Sun Microsystems at InformIT.
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