1. Home
    2. /
  2. Manuals
    3. /
  3. Zyxel
    4. /
  4. VMG4381-B10A
    5. /
  5. 25
Page 121 / 150 Scroll up to view Page 116 - 120
Chapter 7 Wireless
VMG4381-B10A User’s Guide
121
Because of the damage that can be done by a malicious attacker, it’s not just people who have
sensitive information on their network who should use security. Everybody who uses any wireless
network should ensure that effective security is in place.
A good way to come up with effective security keys, passwords and so on is to use obscure
information that you personally will easily remember, and to enter it in a way that appears random
and does not include real words. For example, if your mother owns a 1970 Dodge Challenger and
her favorite movie is Vanishing Point (which you know was made in 1971) you could use
“70dodchal71vanpoi” as your security key.
The following sections introduce different types of wireless security you can set up in the wireless
network.
7.10.3.1
SSID
Normally, the Device acts like a beacon and regularly broadcasts the SSID in the area. You can hide
the SSID instead, in which case the Device does not broadcast the SSID. In addition, you should
change the default SSID to something that is difficult to guess.
This type of security is fairly weak, however, because there are ways for unauthorized wireless
devices to get the SSID. In addition, unauthorized wireless devices can still see the information that
is sent in the wireless network.
7.10.3.2
MAC Address Filter
Every device that can use a wireless network has a unique identification number, called a MAC
address.
1
A MAC address is usually written using twelve hexadecimal characters
2
; for example,
00A0C5000002 or 00:A0:C5:00:00:02. To get the MAC address for each device in the wireless
network, see the device’s User’s Guide or other documentation.
You can use the MAC address filter to tell the Device which devices are allowed or not allowed to
use the wireless network. If a device is allowed to use the wireless network, it still has to have the
correct information (SSID, channel, and security). If a device is not allowed to use the wireless
network, it does not matter if it has the correct information.
This type of security does not protect the information that is sent in the wireless network.
Furthermore, there are ways for unauthorized wireless devices to get the MAC address of an
authorized device. Then, they can use that MAC address to use the wireless network.
7.10.3.3
User Authentication
Authentication is the process of verifying whether a wireless device is allowed to use the wireless
network. You can make every user log in to the wireless network before using it. However, every
device in the wireless network has to support IEEE 802.1x to do this.
For wireless networks, you can store the user names and passwords for each user in a RADIUS
server. This is a server used in businesses more than in homes. If you do not have a RADIUS server,
you cannot set up user names and passwords for your users.
Unauthorized wireless devices can still see the information that is sent in the wireless network,
even if they cannot use the wireless network. Furthermore, there are ways for unauthorized
1.
Some wireless devices, such as scanners, can detect wireless networks but cannot use wireless networks. These kinds
of wireless devices might not have MAC addresses.
2.
Hexadecimal characters are 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, and F.
Page 122 / 150
Chapter 7 Wireless
VMG4381-B10A User’s Guide
122
wireless users to get a valid user name and password. Then, they can use that user name and
password to use the wireless network.
7.10.3.4
Encryption
Wireless networks can use encryption to protect the information that is sent in the wireless
network. Encryption is like a secret code. If you do not know the secret code, you cannot
understand the message.
The types of encryption you can choose depend on the type of authentication. (See
Section
7.10.3.3 on page 121
for information about this.)
For example, if the wireless network has a RADIUS server, you can choose
WPA
or
WPA2
. If users
do not log in to the wireless network, you can choose no encryption,
Static WEP
,
WPA-PSK
, or
WPA2-PSK
.
Usually, you should set up the strongest encryption that every device in the wireless network
supports. For example, suppose you have a wireless network with the Device and you do not have
a RADIUS server. Therefore, there is no authentication. Suppose the wireless network has two
devices. Device A only supports WEP, and device B supports WEP and WPA. Therefore, you should
set up
Static WEP
in the wireless network.
Note: It is recommended that wireless networks use
WPA-PSK
,
WPA
, or stronger
encryption. The other types of encryption are better than none at all, but it is still
possible for unauthorized wireless devices to figure out the original information
pretty quickly.
When you select
WPA2
or
WPA2-PSK
in your Device, you can also select an option (
WPA
compatible
) to support WPA as well. In this case, if some of the devices support WPA and some
support WPA2, you should set up
WPA2-PSK
or
WPA2
(depending on the type of wireless network
login) and select the
WPA compatible
option in the Device.
Many types of encryption use a key to protect the information in the wireless network. The longer
the key, the stronger the encryption. Every device in the wireless network must have the same key.
7.10.4
Signal Problems
Because wireless networks are radio networks, their signals are subject to limitations of distance,
interference and absorption.
Problems with distance occur when the two radios are too far apart. Problems with interference
occur when other radio waves interrupt the data signal. Interference may come from other radio
transmissions, such as military or air traffic control communications, or from machines that are
Table 30
Types of Encryption for Each Type of Authentication
NO AUTHENTICATION
RADIUS SERVER
Weakest
No Security
WPA
Static WEP
WPA-PSK
Strongest
WPA2-PSK
WPA2
Page 123 / 150
Chapter 7 Wireless
VMG4381-B10A User’s Guide
123
coincidental emitters such as electric motors or microwaves. Problems with absorption occur when
physical objects (such as thick walls) are between the two radios, muffling the signal.
7.10.5
BSS
A Basic Service Set (BSS) exists when all communications between wireless stations or between a
wireless station and a wired network client go through one access point (AP).
Intra-BSS traffic is traffic between wireless stations in the BSS. When Intra-BSS traffic blocking is
disabled, wireless station A and B can access the wired network and communicate with each other.
When Intra-BSS traffic blocking is enabled, wireless station A and B can still access the wired
network but cannot communicate with each other.
Figure 45
Basic Service set
7.10.6
MBSSID
Traditionally, you need to use different APs to configure different Basic Service Sets (BSSs). As well
as the cost of buying extra APs, there is also the possibility of channel interference. The Device’s
MBSSID (Multiple Basic Service Set IDentifier) function allows you to use one access point to
provide several BSSs simultaneously. You can then assign varying QoS priorities and/or security
modes to different SSIDs.
Wireless devices can use different BSSIDs to associate with the same AP.
7.10.6.1
Notes on Multiple BSSs
•
A maximum of eight BSSs are allowed on one AP simultaneously.
Page 124 / 150
Chapter 7 Wireless
VMG4381-B10A User’s Guide
124
•
You must use different keys for different BSSs. If two wireless devices have different BSSIDs
(they are in different BSSs), but have the same keys, they may hear each other’s
communications (but not communicate with each other).
•
MBSSID should not replace but rather be used in conjunction with 802.1x security.
7.10.7
Preamble Type
Preamble is used to signal that data is coming to the receiver. Short and long refer to the length of
the synchronization field in a packet.
Short preamble increases performance as less time sending preamble means more time for sending
data. All IEEE 802.11 compliant wireless adapters support long preamble, but not all support short
preamble.
Use long preamble if you are unsure what preamble mode other wireless devices on the network
support, and to provide more reliable communications in busy wireless networks.
Use short preamble if you are sure all wireless devices on the network support it, and to provide
more efficient communications.
Use the dynamic setting to automatically use short preamble when all wireless devices on the
network support it, otherwise the Device uses long preamble.
Note: The wireless devices MUST
use the same preamble mode in order to communicate.
7.10.8
Wireless Distribution System (WDS)
The Device can act as a wireless network bridge and establish WDS (Wireless Distribution System)
links with other APs. You need to know the MAC addresses of the APs you want to link to. Once the
security settings of peer sides match one another, the connection between devices is made.
At the time of writing, WDS security is compatible with other ZyXEL access points only. Refer to
your other access point’s documentation for details.
The following figure illustrates how WDS link works between APs. Notebook computer
A
is a
wireless client connecting to access point
AP 1
.
AP 1
has no wired Internet connection, but it can
establish a WDS link with access point
AP 2
, which has a wired Internet connection. When
AP 1
has a WDS link with
AP 2
, the notebook computer can access the Internet through
AP 2
.
Figure 46
WDS Link Example
7.10.9
WiFi Protected Setup (WPS)
Your Device supports WiFi Protected Setup (WPS), which is an easy way to set up a secure wireless
network. WPS is an industry standard specification, defined by the WiFi Alliance.
WDS
AP 2
AP 1
A
Page 125 / 150
Chapter 7 Wireless
VMG4381-B10A User’s Guide
125
WPS allows you to quickly set up a wireless network with strong security, without having to
configure security settings manually. Each WPS connection works between two devices. Both
devices must support WPS (check each device’s documentation to make sure).
Depending on the devices you have, you can either press a button (on the device itself, or in its
configuration utility) or enter a PIN (a unique Personal Identification Number that allows one device
to authenticate the other) in each of the two devices. When WPS is activated on a device, it has two
minutes to find another device that also has WPS activated. Then, the two devices connect and set
up a secure network by themselves.
7.10.9.1
Push Button Configuration
WPS Push Button Configuration (PBC) is initiated by pressing a button on each WPS-enabled
device, and allowing them to connect automatically. You do not need to enter any information.
Not every WPS-enabled device has a physical WPS button. Some may have a WPS PBC button in
their configuration utilities instead of or in addition to the physical button.
Take the following steps to set up WPS using the button.
1
Ensure that the two devices you want to set up are within wireless range of one another.
2
Look for a WPS button on each device. If the device does not have one, log into its configuration
utility and locate the button (see the device’s User’s Guide for how to do this - for the Device, see
Section 7.6 on page 114
).
3
Press the button on one of the devices (it doesn’t matter which). For the Device you must press the
WPS button for more than three seconds.
4
Within two minutes, press the button on the other device. The registrar sends the network name
(SSID) and security key through an secure connection to the enrollee.
If you need to make sure that WPS worked, check the list of associated wireless clients in the AP’s
configuration utility. If you see the wireless client in the list, WPS was successful.
7.10.9.2
PIN Configuration
Each WPS-enabled device has its own PIN (Personal Identification Number). This may either be
static (it cannot be changed) or dynamic (in some devices you can generate a new PIN by clicking
on a button in the configuration interface).
Use the PIN method instead of the push-button configuration (PBC) method if you want to ensure
that the connection is established between the devices you specify, not just the first two devices to
activate WPS in range of each other. However, you need to log into the configuration interfaces of
both devices to use the PIN method.
When you use the PIN method, you must enter the PIN from one device (usually the wireless client)
into the second device (usually the Access Point or wireless router). Then, when WPS is activated
on the first device, it presents its PIN to the second device. If the PIN matches, one device sends
the network and security information to the other, allowing it to join the network.
Take the following steps to set up a WPS connection between an access point or wireless router
(referred to here as the AP) and a client device using the PIN method.

Rate

4 / 5 based on 1 vote.

Popular Zyxel Models

Famous Router IPs
Famous Router Companies
Bookmark Our Site

Press Ctrl + D to add this site to your favorites!

Share
Top