FOSS Network Infrastructure and Security/Network Concepts and Architectures
Foreword — List of Abbreviations — Introduction to FOSS and GNU/Linux — Network Concepts and Architectures — Major Networking Functions with FOSS — Security Functions with FOSS — Network Planning — Further References — Glossary — About the Author — Acknowledgements — About APDIP — About IOSN
Computer Networks
A network is a mechanism that enables distributed computers and users to communicate and share resources. Sharing of resources may mean sharing a printer, a scanner or even a large hard disk on a particular computer. A computer network connects two or more computers or peripherals so that all users on the network have access to these resources.
There are two major types of computer networks:
- Server-based networks; and
- Peer-to-peer networks.
In a server-based network, there exists one or more computer(s) on which the resources are centralized. The network is also more or less controlled by the server. Servers generally have superior processing power, memory and hard disk space compared to desktop systems.
In a peer-to-peer network, all computers on the network are responsible for sharing resources. Each computer shares the resources that it has. All computers are servers as well as clients. There is no central control over the resources. Peer-to-peer networks are based on peer relationships among computers in the network.
Network Topology
Topology refers to the arrangement of computers in a network. In physical terms, there are two main topologies that are commonly used:
- Bus topology; and
- Star topology
The simplest arrangement is Bus topology in which all computers are connected in a series to a single stretch of cable. This means that the entire length of the cable must be intact for the network to work properly; which makes larger networks prone to failure.
A hub or a switch is used as the central exchange point in a Star topology. All computers are connected to the hub in a star-like configuration of wires going in all directions from the hub. A Star topology is easier to maintain and to expand.