COMP 3000 2011 Report: ZeroShell

ZeroShell

Introduction

ZeroShell is a Linux distribution developed by Fulvio Ricciardi (1), a system administrator at the Italian National Institute of Nuclear Physics’ (INFN) Lecce Section (2). Its purpose is to provide advanced LAN services, e.g. for an office building. Some of these services are:

• Firewall: Enables forwarding of wanted traffic and blocking of unwanted traffic.
• DHCP and DNS server: Lets clients in the network automatically receive an IP address (DHCP) and communicate using identifiers instead of IP addresses (DNS).

... and many more. The use of some of these features will be discussed in more detail in the Basic Operation section.

ZeroShell is not based on another Linux distribution; it is built from the Linux source code using Linux from scratch (3). However, most of the services ZeroShell provides, e.g. OpenVPN (4) and httpd (Apache) (5), are developed by open source development groups, and then included in this multi-purpose network management tool (2).

Intended Purpose

One of the most important parts of providing advanced network services is having the right hardware. Most systems will therefore use dedicated embedded devices. For the group of network administrators that would use such devices, the good news is that ZeroShell can be installed on these devices as well as on a computer / server (6). Hence, ZeroShell enables the use of far more advanced services than some of the original operating systems on these devices.

ZeroShell also opens up another possibility: instead of acquiring embedded devices to provide the necessary services, ZeroShell can be installed on a server. Even better, it can be installed on a virtual computer running in parallel with other servers. For example, it can provide network services to a web server running on the same hardware.

Hardware Requirements

The hardware required to run ZeroShell is minimal (6):