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Communication Security: Wireless • Chapter 4 229

Site Surveys

A site survey is part of an audit done on wireless networks. Site surveys allow
system and network administrators to determine the extent to which their wireless
networks extend beyond the physical boundaries of their buildings.Typically, a site
survey uses the same tools an attacker uses, such as a sniffer and a WEP cracking
tool (for 802.11 network site surveys).The sniffer can be either Windows-based
such as NetStumbler or UNIX/Linux-based such as Kismet. For WEP cracking,
AirSnort is recommended.
Other tools that can be useful are a directional antenna such as a Yagi antenna
or a parabolic dish antenna. Directional and parabolic dish antennae allow for the
reception of weak signals from greater distances by providing better amplification
and gain on the signal.These antennae allow wireless network auditors the ability
to determine how far an attacker can realistically be from the source of the wireless
network transmissions in order to receive from and transmit to the network.
Finally, another tool that is useful for site surveys is a GPS locator.This provides
for the determination of the geographical latitude and longitude of areas where
wireless signal measurements are taken. Using GPS, auditors can create a physical
map of the boundaries of the wireless network.

EXAM WARNING

Site surveys are not covered extensively in the Security+ exam. However,
there may be a question about some of the tools used to conduct these
surveys. Remember that the tools used to conduct site surveys and
audits are essentially the same tools an attacker uses to gain access to a
wireless network. Be prepared in case a Security+ exam question asks
whether a particular tool is used in wireless network site surveys.

Additional Security
Measures for Wireless Networks

Although 802.1x authentication provides good security through the use of dynami-
cally generated WEP keys, security administrators may wish to add more layers of
security.Additional security for wireless networks can be introduced through the
design of the network itself.As stated previously, a wireless network should always

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