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Security Risks and Ways to Decrease Vulnerabilities in a 802.11b Wireless Environment

2008-06-10来源:

Introduction

This document explains topics relating to wireless networks. The main topics discussed include, what type of vulnerabilities exist today in 802.11 networks and ways that you can help prevent these vulnerabilities from happening. Wireless networks have not been around for many years. Federal Express has been using a type of wireless networks, common to the 802.11 networks used today, but the general public has recently just started to use wireless networking technology. Because of weak security that exists in wireless networks, companies such as Best Buy have decided to postpone the roll-out of wireless technology. The United States Government has done likewise and is suspending the use of wireless until a more universal, secure solution is available.

Background

What is Wireless?

Wireless LANs or Wi-Fi is a technology used to connect computers and devices together. Wireless LANs give persons more mobility and flexibility by allowing workers to stay connected to the Internet and to the network as they roam from one coverage area to another. This increases efficiency by allowing data to be entered and accessed on site.

Besides being very simple to install, WLANs are easy to understand and use. With few exceptions, everything to do with wired LANs applies to wireless LANs. They function like, and are commonly connected to, wired Ethernet networks.

The Wireless Ethernet Compatibility Alliance [WECA] is the industry organization that certifies 802.11 products that are deemed to meet a base standard of interoperability. The first family of products to be certified by WECA is that based on the 802.11b standard. This set of products is what we will be studying. Also more standards exist such as 802.11a and 802.11g.

The original 802.11 standard was published in 1999 and provides for data rates at up to 2 Mbps at 2.4 GHz, using either FHSS or DSSS. Since that time many task groups have been formed to create supplements and enhancements to the original 802.11 standard.

The 802.11b TG created a supplement to the original 802.11 standard, called 802.11b, which has become the industry standard for WLANs. It uses DSSS and provides data rates up to 11 Mbps at 2.4 Ghz. 802.11b will eventually be replaced by standards which have better QoS features, and better security.

network Topology

There are two main topologies in wireless networks which can be configured:

Peer-to-peer (ad hoc mode) - This configuration is identical to its wired counterpart, except without the wires. Two or more devices can talk to each other without an AP.

Client/Server (infrastructure networking) - This configuration is identical to its wired counterpart, except without the wires. This is the most common wireless network used today, and what most of the concepts in this paper apply to.

Benefits of Wireless LANs

  • WLANs can be used to replace wired LANs, or as an extension of a wired infrastructure. It costs far less to deploy a wireless LAN than to deploy a wired one. A major cost of installing and modifying a wired network is the expense to run network and power cables, all in accordance with local building codes. Example of additional applications where the decision to deploy WLANs include:

  • Additions or moves of computers.

  • Installation of temporary networks

  • Installation of hard-to-wire locations

    Wireless LANs give you more mobility and flexibility by allowing you to stay connected to the Internet and to the network as you roam.

    Cons of Wireless LANs

    Wireless LANs are a relatively new technology which has only been around since 1999. With any new technology, standards are always improving, but in the beginning are unreliable and i