Telmex

Securing Wireless LANs

January 2003

A White Paper By NetScreen Technologies Inc. http://www.netscreen.com

Table Of Contents
INTRODUCTION.................................................................................................................................. 2 SECURING WIRELESSLANS........................................................................................................... 2 USER AUTHENTICATION ....................................................................................................................... 3 DATA CONFIDENTIALITY ...................................................................................................................... 4 SECURITY REQUIREMENTS.................................................................................................................... 5 HOW NETSCREEN SOLUTIONS CAN HELP ................................................................................ 5 ORGANIZATION A: CENTRALIZED OFFICES WITH VLANS ................................................ 7 REQUIREMENTS: ................................................................................................................................... 7STEP 1: CREATE WIRELESS BACKBONE NETWORK AND ISOLATE WITH NETSCREEN FIREWALL ............ 8 STEP 2: ACCESS CONTROL POLICY – HOW IT WORKS .......................................................................... 9 STEP 3: IPSEC VPN OVER WLAN........................................................................................................ 9 ORGANIZATION B: DEPARTMENTAL ACCESS-POINTS...................................................... 10 REQUIREMENTS: ................................................................................................................................. 10 STEP 1: NETWORK TOPOLOGY CONFIGURATION................................................................................. 11 STEP 2: ACCESS CONTROL POLICY – HOW IT WORKED...................................................................... 12 CONCLUSION .................................................................................................................................... 12 SOURCES CITED ............................................................................................................................... 13 GLOSSARY OFTERMS.................................................................................................................... 13

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Introduction
Wireless Local Area Networks (WLANs) offer great potential to provide users with increased efficiency and productivity. The goal of WLANs is to enable users to connect to the network without having to be physically attached to it, making it possible for workers on the go to stay connected to the people andinformation they need to do their job. Unfortunately, because they were designed with access in mind, not security, the implementation of current WLAN protocols open the network up to well-known risks, with inadequate authentication and encryption, plus a lack of granular control. IT professionals considering WLAN need to weigh the trade-off between providing simple access and security. Someconsider this trade-off as the single greatest barrier to WLAN adoption. According to a reader poll conducted by Network Computing in January 2002, over 80% of enterprise network administrators consider security the biggest barrier to implementing WLANs. Nevertheless, wireless adoption rates are on the rise. Gartner Dataquest “forecasts the penetration rate of wireless LAN into the professional mobilePC installed base will grow from 9 percent in 2000 to almost 50 percent by the end of 2003, and it is expected to surpass 90 percent by 2007.”1 To drive the adoption, the WLAN industry has tried to address the user authentication and data confidentiality issues to add security and reduce the risk posed by wireless devices. Unfortunately, the standards, 802.1X (for user authentication) and WEP...