Hardware Requirements  «Prev  Next»
Lesson 7 Security hardware
Objective Describe Security Devices and the Problems they may cause.

Security Hardware Problems caused by Devices

Web sites may fail due to outside attacks by hackers, who manage to gain access to the system and steal or corrupt data. Over the last few years there have been a number of attacks both in the private and the public sectors, which have increased concern about the importance of security hardware.

What is security hardware?

The security hardware's goal is to ensure that data stored in a computer cannot be accessed or altered by unauthorized users. To prevent unauthorized access to or from a private network, such as an intranet, a firewall server is used. The firewall is the first line of defense against unwanted users. All messages entering or leaving the intranet pass through the firewall, which examines each message and blocks those that do not meet the specified security criteria.
  1. UPS: The uninterrupted power supply ensures that electrical power continues to be available during a power outage.
  2. client hardware: Desktop computer, network interface card, and modem
  3. security hardware: Firewall: ensures that data stored in a computer cannot be accessed by unauthorized users.
  4. connectivity hardware: Allows a device or a program to link to other devices or programs.
  5. server hardware: A remote device shared by many users. It may store a particular resource, such as Web pages, or perform specific functions, such as forwarding and receiving email.

Firewall as Part of Network
There are three types of firewalls, varying in complexity and level of security. These are:
  1. packet-level gateway
  2. application-level gateway
  3. circuit-level gateway

1) Packet-level gateway

The packet-level gateway is the most basic and inexpensive kind of firewall. It consists of a router configured with standard packet-filtering that scans each packet's header for authorized IP addresses and specified types of traffic. Unauthorized packets are simply discarded.

2) Application-level gateway

The application-level gateway (proxy server) is more secure than the packet-level gateway and harder to configure. It acts as an intermediary between clients and servers and uses server programs called proxies to examine external requests and forwards authorized requests to the appropriate internal host.

3) Circuit-level gateway

The circuit-level gateway relays TCP connections. It copies bytes back and forth from either side of the firewall creating a virtual circuit. It's best for trusted internal users who also need to do work outside the firewall. It's the safest of the three types of firewalls, but also the most difficult to configure.

Common problems of security hardware

Users may experience problems caused by their own security hardware. For example, a user may not be able to access or download from certain Web sites if the firewall configuration is faulty or if there is a router IP filtering problem. A faulty firewall configuration or the lack of sufficient client memory may also cause errors when the user attempts to download plug-ins.

Three types of Firewalls

There are three different types of firewalls. They vary in cost as well as level of configuration complexity and safety.
From the simplest to the most complex, these firewalls are known as Packet-level gateways, Application-level gateways, and Circuit-level gateways.
In the next lesson, you will learn about strategies for dealing with common hardware risks.