802.11 Networks on Windows XP

When creating a Windows XP-based 802.11b wireless network, there are
three primary points of consideration: user administration, key management,
and security

User Administration
Whenever you need to integrate user administration tools into a wireless
network, there are several points to consider. Whenever you create
a wireless-enabled user group, any user who is part of this group can
access all resources through these wireless tools.
When administering a large network, it is important to maintain
some sanity in keeping track of everyone. It is easiest to identify users
through their usernames in larger wireless networks. Using the
machine address of each user’s individual network interface card as a
means to track each user is very cumbersome. It is acceptable to restrict
access based on the machine/MAC address so that you can prevent
unauthorized users from accessing your network, but using that information
to keep track of every user is very difficult and impractical.

When you keep track of users by their usernames, you can also check
the log information on user activity to determine if there are any unusual
types of hacking activities. Information you can keep
track of for each username includes:


Network usage

Time accounting (hours of usage)

Auditing of user activity

If there is a spike in network usage at any time, then it is possible
that the user’s identity has been stolen and that his account is being
used to gain unauthorized network access. Keeping track of usage helps
you determine these spikes more easily. This allows you to maintain an
open system for authorized users, but a closed one for those not authorized
to use your WLAN.
Time accounting is a good method of determining who should be
using the WLAN and when. If you know that a user is supposed to be
using the network within standard work hours, but there is an inordinate
amount of usage before or after the specified working hours, then it
becomes a good possibility that someone else is using that person’s wireless
account to gain unauthorized access to network resources. Good
time accounting helps you keep track of unusual usage patterns that
can constitute a network breach.
Auditing user activity helps you determine if a pattern exists that might
show a breach of your network. Many intrusion detection systems audit
usage logs in an attempt to determine if there is a pattern that might indicate
a hacker at work. In fact, audit logs are even used by certain agencies
to track down and find hackers who gain unauthorized access to your network
during off hours. This process helps your administrators determine if
improper activity originates from both authorized and unauthorized users.