Intel 2011B - PRO/Wireless LAN Enterprise Access... User manual

Intel® PRO/Wireless 2011/2011B LAN
Configuring Access Point Bridging and Repeating (WLAP
Mode)

ii Configuring Access Point Bridging and Repeating (WLAP Mode)
Product Model
Intel® PRO/Wireless 2011/2011B LAN Adapter product models:
WEAP2011NA
WEAP2011EU
WEAP2011JP
WEAP2011AR
WEAP2011SG
WEAP2011KR
WEAP2011EO
WEAP2011BAK
WEAP2011BRW
WEAP2011BJP
Copyright
Copyright © 2001, 2002 Intel Corporation. All rights reserved.
Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
Intel Corporation assumes no responsibility for errors or omissions in this document. Nor does Intel make any commitment to update the
information contained herein.
Intel® PRO/Wireless 2011/2011B LAN is a registered trademark of Intel Corporation.
†Other product and corporate names mentioned herein may be trademarks of other companies and are used only for explanation and to the owners’
benefit, without intent to infringe.
A79771-001

About This Document
Configuring Access Point Bridging and Repeating (WLAP Mode) iii
About This Document
Conventions
Keystrokes are indicated as follows:
Typeface conventions used include.
ENTER identifies a key.
FUNC, CTRL, Cidentifies a key sequence. Press and release each key in turn.
Press A+B press the indicated keys simultaneously.
Hold A+B press and hold the indicated keys while performing or waiting for another
function. Used in combination with another keystroke.
<angles> indicates mandatory parameters in syntax.
[brackets] for command line, indicates available parameters; in configuration files,
brackets act as separators for options.
GUI Screen text indicates the name of a control in a GUI-based application.
Italics indicates the first use of a term, book title, variable or menu title.
Bold indicates important user information, license provisions or warranty
conditions.
Screen dialog indicates screen dialog and user input options, and the exact syntax of items.
Screen text indicates text and data displayed in an application screen on a computer
monitor.
Terminal text
Terminal textTerminal text
Terminal text indicates text shown in a radio terminal LCD screen.
URL indicates a Uniform Resource Locator, such as a Web page address.

About This Document
iv Configuring Access Point Bridging and Repeating (WLAP Mode)
This document uses the following for certain conditions or information:
indicates tips or special requirements.
indicates conditions that can cause equipment damage or data loss.
indicates a potentially dangerous condition or procedure that only Intel®PRO/Wireless 2011/
2011B LAN-trained personnel should attempt to correct or perform.

Contents
Configuring Access Point Bridging and Repeating (WLAP Mode) v
Product Model.............................................................................................................. ii
Copyright...................................................................................................................... ii
About This Document.................................................................................iii
Conventions................................................................................................................ iii
Contents......................................................................................................v
Chapter 1. Introduction.....................................................................................................................1
1.1 Basic Settings for Access Points............................................................................1
1.2 Recommended Settings for Root Access Point .....................................................2
Chapter 2. Extending a Network’s Radio Coverage................................................................4
2.1 One-Hop Wireless Network Example.....................................................................4
2.2 Two-Hop Wireless Network Example.....................................................................4
Chapter 3. Verifying Wireless AP Operations............................................................................6
3.1 Viewing the WLAP RF Statistics Screen................................................................6
3.2 Viewing the Known Access Points Screen.............................................................7
3.3 Observing the Access Point’s LED Indicators........................................................8
3.3.1 Functional State............................................................................................9
3.3.2 Send Probe State .........................................................................................9
Chapter 4. Using the Link Required Option..............................................................................11
4.1 Link Required for Maintaining Ethernet Link ........................................................11
4.2 Link Required for Backing Up Root Access Point................................................13
Chapter 5. Bridging Two Ethernet Networks............................................................................16
5.1 Verifying the Bridging Operation ..........................................................................16
5.2 Using the Ethernet Timeout Settings 2 & 3..........................................................17
5.2.1 Ethernet Timeouts and Access Point Settings............................................18
5.2.2 Sequence of Events in Special Network.....................................................20
5.3 Using the Ethernet Timeout Setting 4..................................................................21
Chapter 6. RF Link Test.................................................................................................................22
6.1 Basic Setup for the RF Link Test .........................................................................22
6.2 The Connection Quality Test Screen...................................................................23
6.2.1 Low and Zero RSSI Readings....................................................................24
6.3 Preparing for the RF Link Test.............................................................................25
6.4 Running the RF Link Test ....................................................................................25
6.4.1 Running the RF Link Test with Telnet.........................................................27
6.5 Using RF Link Test with Mobile Units ..................................................................29
6.6 Using RF Link Test to Align Directional Antennas ...............................................30
6.6.1 Setting Up for the Antenna Alignment Procedure.......................................31
6.6.2 Procedure for Aligning Directional Antennas..............................................32
6.6.3 Additional Suggestions on Antenna Alignment...........................................34
Omni-Directional Antenna...........................................................................................34
Contents

Contents
vi Configuring Access Point Bridging and Repeating (WLAP Mode)
Other Equipment.........................................................................................................35
Chapter 7. Regulatory Compliance Information......................................................................36
Index.........................................................................................................................................................37

Configuring Access Point Bridging and Repeating (WLAP Mode) 1
Chapter 1. Introduction
This document describes how to set up an Intel®PRO/Wireless 2011/2011B LAN Access Point.
For the Intel®PRO/Wireless 2011B LAN Access Point, the firmware is version 3.x. For the Intel®
PRO/Wireless 2011 LAN Access Point, the firmware is version 2.5x.
The features in the access point firmware allow network communication between access points.
You can use access points to extend radio coverage of a single Ethernet network or to bridge two
Ethernet networks.
A wireless network consists of a root Wireless Access Point (WLAP) and one or more designated
WLAPs. The root access point is typically connected to the Ethernet network; although, this is not
a requirement. The network in Figure 1-1 uses two access points operating in the wireless mode to
extend radio coverage. The solid line in the figure represents an Ethernet network.
Figure 1-1: Extending Network Radio Coverage Using Wireless Access Points
Access points maintain their wireless connections through the radio broadcasting of probe, beacon,
and Bridge Protocol Data Unit (BPDU) messages. Probe and beacon messages are part of the
802.11 protocol. BPDU messages are part of the Spanning Tree Protocol.
At the start of a wireless connection, access points send out probe requests and probe responses to
gather operating status of other access points. Designated WLAPs also send out probes if they lose
the beacon message from the root access point. The beacon messages are broadcast by the access
points to keep the network synchronized. It contains information such as the access point’s
Extended Service Set Identifier (ESS ID) and MAC address. The ESS ID is also called the Network
Name or SSID.
There are two types of BPDU messages. One type is a configuration BPDU. At the start of the
wireless connection, the configuration BPDU messages determine the network configuration for
the root access point and designated WLAPs. The other type of BPDU is the WLAP-Alive. These
messages keep track of access points operating in the wireless network.
The procedures and examples in this document are for Intel®PRO/Wireless 2011 and 2011B LAN
Access Points with firmware version 2.5x or higher. Additional information on access points is
available in the Intel®PRO/Wireless 2011/2011B LAN Point Product Reference Guides available
on the Intel support web site at www.support.Intel.com.
1.1 Basic Settings for Access Points
For a wireless Access Point (AP) operation, make sure that all access points have:
•The same ESS ID (Net ID) on the Access Point Installation screen. An example screen is
A
BC

Chapter 1. Introduction
2 Configuring Access Point Bridging and Repeating (WLAP Mode)
shown in Figure 1-2. The ESS ID is sometimes referred to as a SSID or Network Name.
•The WLAP Mode set to Enabled. This setting is on the RF Configuration screen. An example
screen is shown in Figure 1-3.
•The same settings for the Rate Control and Short RF Preamble. These settings are on the RF
Configuration screen. An example is shown in Figure 1-3. Rates set to Required are those at
which all access points in the network must be capable of operating. Optional rates are those at
which access points may operate if they are capable. This is to accommodate other
manufacturers’access points that operate only at the 1- and 2-Mbps rates. For example, if all
rates are set to Required, older access points that operate at only 1 and 2 Mbps would not
associate. If only the 1- and 2-Mbps rates (or only the 1-Mbps rate) are set to Required, the
older access points would associate. Intel recommends setting rates 1 and 2 Mbps to Required
and 5.5 and 11 Mbps to Optional as shown in the example screen of Figure 1-3.
•The same setting for the Wired Equivalent Privacy (WEP) and WEP Algorithm. These settings
are on the RF Configuration screen. An example is shown in Figure 1-3.
After making these settings, save them by pressing the F1 key. Reset the access point.
Figure 1-2: Setting the ESS ID (Network Name/SSID)
1.2 Recommended Settings for Root Access Point
On the root access point, pay attention to the following settings on the RF Configuration screen, as
shown on Figure 1-3:
•WLAP Priority
•WLAP Manual BSS ID
WLAP Priority
Set the root access point’s WLAP Priority setting to a lower number such as 7000 hex. The default
value for the WLAP Priority setting is 8000 hex, and it has a range from 0000 through FFFF hex.
Changing the WLAP Priority to a lower number ensures that the access point is recognized as the
root access point. A WLAP ID is created for each access point from a concatenation of its WLAP
Priority number and its MAC address. The priority number becomes the most-significant portion of
the WLAP ID. The access point with the lowest WLAP ID becomes the root access point.
Access Point A Access Point Installation
.Country Config-[CR] United States
Unit Name Access Point A .Additional Gateways
IP Address 157.235.55.199 0.0.0.0
.Gateway IP Address 0.0.0.0 0.0.0.0
0.0.0.0
.Subnet Mask 255.255.255.0 0.0.0.0
0.0.0.0
.DNS IP Address 0.0.0.0 0.0.0.0
0.0.0.0
.Net_ID (ESS) Warehouse 1 .Additional DNS
.Antenna Selection Full Diversity 0.0.0.0
.DHCP/BOOTP Disabled 0.0.0.0
OK-[CR] Save-[F1] Save All APs-[F2] Cancel-[ESC]
(Most parameters take effect only after being saved and AP is reset)
Identifies this Wireless LAN (1-32 characters)

Configuring Access Point Bridging and Repeating (WLAP Mode) 3
After the wireless network is running, observe the WLAP ID from the WLAP RF Statistics screen.
Display this screen by pressing F3 from the RF Statistics screen.
WLAP Manual BSS ID
Intel recommends that you set the WLAP Manual BSS ID to its own MAC address. An example is
shown in Figure 1-3. This causes the access point to go directly to the Functional state and therefore
reduces the time required to begin the wireless connection. The Functional state is described in
section 3.3.1: Functional State.
Figure 1-3: Example Settings for the Root Access Point
Access Point A RF Configuration
.DTIM Interval 10 WLAP Mode Enabled
.BC/MC Q Max 10
.Max Retries (d) 15 WLAP Priority 7000 hex
.Max Retries (v) 5 WLAP Manual BSS ID 00:A0:F8:93:C5:B5
.Multicast Mask (d) 09000E00 hex
.Multicast Mask (v) 01005E00 hex WLAP Hello Time 20
.Beacon Interval 100 K-us WLAP Max Age 100
.Accept Broadcast ESSID Disabled WLAP Forward Delay 5
.MU Inactivity Timeout 60 min. WLAP MU Table Aging Time 240 min.
.Rate Control
11 Mb/s Optional .WEP (Privacy) Disabled
5.5 Mb/s Optional .WEP Algorithm 40 bit shared key
2 Mb/s Required .Encryption Key ID 1
1 Mb/s Required Encryption Key Maintenance
.RTS Threshold 2347 bytes .Short RF Preamble Disabled
Extended Range 0 mi. Tx Power Control Full
OK-[CR] Save-[F1] Save All APs-[F2] Cancel-[ESC]
Use the space bar to enable/disable/set link required WLAP operation.

Chapter 2. Extending a Network’s Radio Coverage
4 Configuring Access Point Bridging and Repeating (WLAP Mode)
Chapter 2. Extending a Network’s Radio Coverage
This section covers examples for extending the radio coverage of a single Ethernet network with
one-hop and two-hop wireless AP operations. The term “hop”refers to the direct communications
link between two nodes of a network. With regard to wireless AP operations, the number of hops
refers to the number of direct links through which a message passes between the root access point
and a particular designated WLAP. Examples of one-hop and two-hop operations are shown in
Figure 2-1 and Figure 2-2.
The basic settings for the access points are covered in the previous sections. In the following
network diagram examples, the root access point is labeled A, and the two designated WLAPs are
labeled B and C. For reference, the MAC addresses are included in the diagrams and example
screens.
Figure 2-1: Wireless AP Network with One Hop
2.1 One-Hop Wireless Network Example
The example in Figure 2-1 extends a network’s radio coverage with one hop between the root
access point A and the two designated WLAPs B and C.
To configure the one-hop network, set the WLAP Manual BSS ID on the root access point to its
own MAC address. In addition, set the WLAP Manual BSS ID on access point B and C to the MAC
address of access point A. The RF Configuration screen for the root access point A is shown in
Figure 2-3.
2.2 Two-Hop Wireless Network Example
The example in Figure 2-2 extends a network’s radio coverage with two hops. In this network, there
is one hop between the root access point A and designated WLAP B, then another hop between
WLAP B and the other designated WLAP C.
To configure a two-hop network, set the WLAP Manual BSS ID on access point C to the MAC
address of access point B and the WLAP Manual BSS ID on B to the MAC address of the root
access point A. The Manual BSS ID for the root access point A is set to its own MAC address. The
RF Configuration screen in Figure 2-3 shows the WLAP Manual BSS ID setting for access point C.
The RF Configuration screens for the other two access points are the same except the WLAP
Manual BSS IDs would be set to 00:A0:F8:93:C5:B5 and the WLAP Priority for access point A
would be set to 7000.
One Hop
Host
Computer
BC
00:A0:F8:8B:71:45 00:A0:F8:94:C3:64
Root access point A
00:A0:F8:93:C5:B5
WLAP Priority = 7000
Ethernet
HOST.CDR, FRAME
WLAP Manual BSS ID
of B and C set to MAC
address of A
WLAP Manual
BSS ID of A set
to its own MAC
address.

Chapter 2. Extending a Network’s Radio Coverage
Configuring Access Point Bridging and Repeating (WLAP Mode) 5
Figure 2-2: Wireless AP Network with Two Hops
Figure 2-3: WLAP Manual BSS ID on Access Point C in 2-Hop Network
Two
Hops
Host
Computer
B
C
00:A0:F8:8B:71:45
00:A0:F8:94:C3:64
Root access point A
00:A0:F8:93:C5:B5
WLAP Priority = 7000
Ethernet
HOST.CDR, FRAME WLAP Manual BSS ID set to
MAC address of access point B.
WLAP Manual BSS ID
set to MAC address
of access point A.
WLAP Manual BSS
IDofA settoitsown
MAC address.
Access Point C RF Configuration
.DTIM Interval 10 WLAP Mode Enabled
.BC/MC Q Max 10
.Max Retries (d) 15 WLAP Priority 8000 hex
.Max Retries (v) 5 WLAP Manual BSS ID 00:A0:F8:8B:71:45
.Multicast Mask (d) 09000E00 hex
.Multicast Mask (v) 01005E00 hex WLAP Hello Time 20
.Beacon Interval 100 K-us WLAP Max Age 100
.Accept Broadcast ESSID Disabled WLAP Forward Delay 5
.MU Inactivity Timeout 60 min. WLAP MU Table Aging Time 240 min.
.Rate Control
11 Mb/s Optional .WEP (Privacy) Disabled
5.5 Mb/s Optional .WEP Algorithm 40 bit shared key
2 Mb/s Required .Encryption Key ID 1
1 Mb/s Required Encryption Key Maintenance
.RTS Threshold 2347 bytes .Short RF Preamble Disabled
Extended Range 0 mi. Tx Power Control Full
OK-[CR] Save-[F1] Save All APs-[F2] Cancel-[ESC]
Enter the desired WLAP MAC addr, with which this AP is going to associate.

Chapter 3. Verifying Wireless AP Operations
6 Configuring Access Point Bridging and Repeating (WLAP Mode)
Chapter 3. Verifying Wireless AP Operations
You can verify wireless AP operations by looking at the following screens:
•WLAP RF Statistics
•Known Access Points
3.1 Viewing the WLAP RF Statistics Screen
Verify the wireless AP operations by viewing the WLAP RF Statistics screen. To view this screen,
select Show RF Statistics from the access point’s Main Menu, then press Enter. This displays the
RF Statistics screen.
From the RF Statistics screen, press F3. This displays the WLAP RF Statistics screen. An example
is shown in Figure 3-1.
During a wireless AP operation, associated access points are listed on the WLAP RF Statistics
screen. The example screen in Figure 3-1 shows that two designated WLAPs have made wireless
links with the root access point. This screen is for the one-hop network example in Figure 3-1.
Notice that the two MAC addresses are listed under the “WLAP Itf Mac Addr”heading and two
FWD states are listed under the “Itf State”heading. The term FWD indicates the forwarding of data
to the associated access point.
For a two-hop network, the statistics in the WLAP RF Statistics screen is shown in Figure 3-2. The
WLAP RF Statistics screen for the root access point lists only one designated WLAP in the FWD
state. However, the WLAP B lists both of the other two access points in the FWD state.
Other possible “Itf”states on the WLAP RF Statistics screen are:
As an access point starts to associate in the wireless AP mode, the state changes from DIS to LIS to
LRN and then finally to FWD indicating association is successful.
Also note that in the example WLAP RF Statistics screens in Figure 3-1 and Figure 3-2, the Current
State entry is Functional, which means that the access point is ready for other access points to
associate with it. However, Functional does not necessarily mean that it has made a wireless AP
connection. Additional information is covered in the section titled 3.3.1: Functional State.
Itf State Definition
DIS Wireless interface is disabled
LIS Access point is listening for configuration information
LRN Access point is learning the configuration information
FWD Access point is forwarding data
BLK Access point is blocking data
Table 3-1: Itf States

Configuring Access Point Bridging and Repeating (WLAP Mode) 7
Figure 3-1: RF Statistics from Root Access Point in One-Hop Network
Figure 3-2: RF Statistics from Access Point B in Two-Hop Network
3.2 Viewing the Known Access Points Screen
The Known Access Points screen lists all access points that are linked together either through a
wireless connection or through a wired connection. You can use the Known Access Points screen to
determine the number of access points in a wireless AP network; however, keep in mind that the
screen also lists access points that are connected to the same Ethernet as the root access point but
may not be part of the wireless AP operation.
Figure 3-3 is an example of a Known Access Points screen listing the root access point and the two
designated WLAPs. This example screen includes another access point connected to the same
Ethernet as the root access point but not in the wireless AP network.
Access Point A WLAP RF Statistics
Current # WLAP Itf 2 Root Interface 0
Root Priority 7000 hex
Current State Functional Root MAC Addr 00:A0:F8:93:C5:B5
Priority 7000 hex Root Path Cost 0
------------- Wireless AP Interface Table ---------------
Itf WLAP Itf Itf Path Designated Designated
ID MAC Addr State Cost Root ID Cost WLAP ID Itf ID
8001 00:A0:F8:8B:71:45 FWD 1 700000a0f893C5B5 0 700000a0f893C5B5 8001
8002 00:A0:F8:94:C3:64 FWD 1 700000a0f893C5B5 0 700000a0f893C5B5 8002
8003 00:00:00:00:00:00 DIS 1 700000a0f893C5B5 0 700000a0f893C5B5 8003
8004 00:00:00:00:00:00 DIS 1 700000a0f893C5B5 0 700000a0f893C5B5 8004
Refresh-[F1] Timed-[F2] Previous-[F4] Exit-[ESC]
Access Point B WLAP RF Statistics
Current # WLAP Itf 2 Root Interface 1
Root Priority 7000 hex
Current State Functional Root MAC Addr 00:A0:F8:93:C5:B5
Priority 8000 hex Root Path Cost 1
------------- Wireless AP Interface Table ---------------
Itf WLAP Itf Itf Path Designated Designated
ID MAC Addr State Cost Root ID Cost WLAP ID Itf ID
8001 00:A0:F8:93:C5:B5 FWD 1 700000a0f893C5B5 0 700000a0f893C5B5 8001
8002 00:A0:F8:94:C3:64 FWD 1 700000a0f893C5B5 1 800000a0f88b7145 8002
8003 00:00:00:00:00:00 DIS 1 800000a0f88b7145 0 800000a0f88b7145 8003
8004 00:00:00:00:00:00 DIS 1 800000a0f88b7145 0 800000a0f88b7145 8004
Refresh-[F1] Timed-[F2] Previous-[F4] Exit-[ESC]

Chapter 3. Verifying Wireless AP Operations
8 Configuring Access Point Bridging and Repeating (WLAP Mode)
Figure 3-3: Known Access Points Showing WLAPs Plus Other
With this screen displayed, you can run an echo test, which performs a PING operation between the
current access point and any of the listed radio-or wired-linked access points. To do this, you use
the Tab key to highlight the access point you wish to PING. Then press F1, followed by the Enter
key to start the echo test.
3.3 Observing the Access Point’s LED Indicators
The access point’s LED indicators and their basic functions are shown in Figure 3-4.
As an access point proceeds through the various states of a wireless AP operation, the LEDs
provide certain status indications. The Intel®PRO/Wireless 2011/2011B LAN Product Reference
Guides describe how the LED indicators are displayed during the several wireless AP operating
states from Initializing through Functional.
Figure 3-4: Access Point LED Indicators and Functions
During normal operation, it may be difficult to observe the LED indicator status because the states
exists for only a very short time. During an abnormal operation, the access point may remain in a
particular state permanently or for a significant length of time. In this situation, you can easily
determine abnormal operation from the status of the LED indicators.
The following subsections cover two of the wireless AP states that you can easily determine by
observing the LED indicators. These two states are: Functional and Send Probe. One of these states
is displayed as the Current State entry on the WLAP RF Statistics screen.
Access Point A Known Access Points
Net_ID: Warehouse 1
MAC Address IP Address CH HST HSQ MUS KBIOS FW_Ver Away
00:A0:F8:93:C5:B5 157.235.55.199 3 - - 0 0 02.51-11
00:A0:F8:8B:71:45 157.235.55.60 1 - - 0 0 02.51-11
00:A0:F8:94:C3:64 157.235.55.198 11 - - 0 0 02.51-11
00:A0:F8:94:C2:04 157.235.55.53 1 - - 0 0 02.51-11
Echo-[F1] Delete-[F2] Next-[F3] Previous-[F4] Switch Exit-[ESC]
Power
Flashes during power-up
sequence (reset).
Continuously on during
operation.
Wired LAN Activity
Flashes when data is
transferred on wired
network.
Wireless LAN Activity
Flickerswhenaccesspoint
sends out beacon signals,
and transfers data to and
from a mobile unit.
ICON GIF
FILES &
FRAME

Configuring Access Point Bridging and Repeating (WLAP Mode) 9
Example screens showing the Current State as “Functional”are shown in Figure 3-1 and Figure 3-
2. An example screen showing the Current State as “Send Probe”is shown in Figure 3-5.
Figure 3-5: Access Point in the Send Probe State
3.3.1 Functional State
The Functional state means that the access point is ready for mobile units or other access points to
associate with it. In this state, the LED indicators display as follows:
Table 3-2: LED Indicators - Functional State
When the access point is in the Functional state, it may or may not have successfully made a
wireless AP connection. You can determine if a wireless AP connection has occurred by viewing
the WLAP RF Statistic screen. If this screen lists one or more access points as being in the FWD
state in the Itf State column, then the current access point has made a wireless AP connection. For
examples of screens showing the FWD state, refer to Figure 3-1 and Figure 3-2.
3.3.2 Send Probe State
Under certain conditions, an access point may remain in the Send Probe state (Figure 3-5) rather
than continue on to the Functional state. In this state, the LED indicators display as follows:
Indicator Activity
Power Remains on
Wired LAN Activity Flashes if activity occurs
Wireless LAN Activity Flickers rapidly
Indicator Activity
Power Remains on
Wired LAN Activity Remains off
Wireless LAN Activity Blinks slowly (once per second)
Access Point A WLAP RF Statistics
Current # WLAP Itf 0 Root Interface 0
Root Priority 8000 hex
Current State Send Probe Root MAC Addr 00:A0:F8:93:C5:B5
Priority 8000 hex Root Path Cost 0
------------- Wireless AP Interface Table ---------------
Itf WLAP Itf Itf Path Designated Designated
ID MAC Addr State Cost Root ID Cost WLAP ID Itf ID
8001 00:00:00:00:00:00 DIS 1 800000a0f893C5B5 0 800000a0f893C5B5 8001
8002 00:00:00:00:00:00 DIS 1 800000a0f893C5B5 0 800000a0f893C5B5 8002
8003 00:00:00:00:00:00 DIS 1 800000a0f893C5B5 0 800000a0f893C5B5 8003
8004 00:00:00:00:00:00 DIS 1 800000a0f893C5B5 0 800000a0f893C5B5 8004
Refresh-[F1] Timed-[F2] Previous-[F4] Exit-[ESC]

Chapter 3. Verifying Wireless AP Operations
10 Configuring Access Point Bridging and Repeating (WLAP Mode)
Table 3-3: LED Indicators - Send Probe State
This occurs when an access point is configured to run in a wireless AP operation but is not
associating with any other access points. The access point remains in the Send Probe state under
one of the following conditions:
a. The access point’s WLAP Mode is set to Enabled and its WLAP Manual BSS ID is set to the
MAC address of another access point.
b. The access point’s WLAP Mode is set to Link Required, it has no Ethernet connection, and its
WLAP Manual BSS ID is set to either the zero default or another access point’s MAC address.
The LED indicators continue to display the Send Probe status until association with another access
point occurs, at which time the access point goes to the Functional state.
Preferred MAC Address. For condition a, if the WLAP Manual BSS ID is set to a “preferred”
MAC address, the access point remains in the Send Probe state for approximately 30 seconds and
then goes to the Functional state. To enter a preferred MAC address, change the first two numbers
of the MAC address from 00 to 01; for example, 01:A0:F8:93:C6:E4. This is sometimes referred to
as turning on the broadcast bit.
No MAC Address. For condition a, if the WLAP Manual BSS ID is set to the zero default value, the
access point remains in the Send Probe state for approximately 30 seconds and then goes to the
Functional state.
Ethernet Connection. For condition b, the Ethernet connection must be restored before the access
point can associate and go to the Functional state.

Chapter 4. Using the Link Required Option
Configuring Access Point Bridging and Repeating (WLAP Mode) 11
Chapter 4. Using the Link Required Option
As shown in Figure 4-1, Link Required is one of the options for the WLAP Mode entry on the RF
Configuration screen. This option allows an access point to create a wireless link in the event it
loses its Ethernet connection.
Link Required can also be used to allow WLAPs to roam to another root access point if the original
root access point loses its Ethernet connection.
Network examples using the Link Required option are covered in the following subsections.
Figure 4-1: Setting the WLAP Mode to Link Required
4.1 Link Required for Maintaining Ethernet Link
As previously mentioned, the Link Required option allows an access point to operate as a WLAP if
it loses its Ethernet connection.
An example network is shown in Figure 4-2. In this example, when access point B loses its Ethernet
connection, it resets then makes a wireless link to the Ethernet through access point A.
Access Point A RF Configuration
.DTIM Interval 10 WLAP Mode Link Required
.BC/MC Q Max 10
.Max Retries (d) 15 WLAP Priority 8000 hex
.Max Retries (v) 5 WLAP Manual BSS ID 00:00:00:00:00:00
.Multicast Mask (d) 09000E00 hex
.Multicast Mask (v) 01005E00 hex WLAP Hello Time 20
.Beacon Interval 100 K-us WLAP Max Age 100
.Accept Broadcast ESSID Disabled WLAP Forward Delay 5
.MU Inactivity Timeout 60 min. WLAP MU Table Aging Time 240 min.
.Rate Control
11 Mb/s Optional .WEP (Privacy) Disabled
5.5 Mb/s Optional .WEP Algorithm 40 bit shared key
2 Mb/s Required .Encryption Key ID 1
1 Mb/s Required Encryption Key Maintenance
.RTS Threshold 2347 bytes .Short RF Preamble Disabled
Extended Range 0 mi. Tx Power Control Full
OK-[CR] Save-[F1] Save All APs-[F2] Cancel-[ESC]
Use the space bar to enable/disable/set link required WLAP operation.

Chapter 4. Using the Link Required Option
12 Configuring Access Point Bridging and Repeating (WLAP Mode)
Figure 4-2: Link Required Operation for Maintaining Ethernet Link
By viewing the WLAP RF Statistics screen, you can determine whether or not a wireless link exists
between access points. In the example network in Figure 4-2, no wireless link exists between the
access points as long as they are both connected to the Ethernet. For this condition, the WLAP RF
Statistics screen (Figure 4-3) shows the Current State as Functional, the Itf State as DIS (disabled),
and the WLAP Itf MAC Addr as zero.
If one of the access points in the network in Figure 4-2 loses its Ethernet connection, it resets and
initiates a wireless connection with the other access point. When the process of making the wireless
link is completed, the WLAP RF Statistics screen (Figure 4-4) shows the Itf State as FWD
(forward) and the WLAP Itf MAC Addr as the MAC address of the other access point.
A
Ethernet
B
Settings on Both Access Points:
WLAP Mode = Link Required.
WLAP Priority = 8000.
WLAP Manual BSS ID = 0.
Ethernet Timeout = 0.
A
Ethernet
B
If an access point loses its Ethernet connection, it resets and makes
a wireless link to the Ethernet through the other access point.

Chapter 4. Using the Link Required Option
Configuring Access Point Bridging and Repeating (WLAP Mode) 13
4.2 Link Required for Backing Up Root Access Point
This section shows how to use the Link Required option so that designated WLAPs can roam to
another root access point if the original one loses its Ethernet connection. In Figure 4-5, access
points B and C are initially the designated WLAPs for root access point A. When access point A’s
Ethernet connection is broken, access points B and C reset then to roam to access point D.
Furthermore, if access point D loses its Ethernet connection and access point A’s Ethernet
connection is restored, WLAPs B and C roams back to access point A.
Access Point A WLAP RF Statistics
Current # WLAP Itf 0 Root Interface 0
Root Priority 8000 hex
Current State Functional Root MAC Addr 00:A0:F8:93:C5:B5
Priority 8000 hex Root Path Cost 0
------------- Wireless AP Interface Table ---------------
Itf WLAP Itf Itf Path Designated Designated
ID MAC Addr State Cost Root ID Cost WLAP ID Itf ID
8001 00:00:00:00:00:00 DIS 1 800000a0f893C5B5 0 800000a0f893C5B5 8001
8002 00:00:00:00:00:00 DIS 1 800000a0f893C5B5 0 800000a0f893C5B5 8002
8003 00:00:00:00:00:00 DIS 1 800000a0f893C5B5 0 800000a0f893C5B5 8003
8004 00:00:00:00:00:00 DIS 1 800000a0f893C5B5 0 800000a0f893C5B5 8004
Refresh-[F1] Timed-[F2] Previous-[F4] Exit-[ESC]
Figure 4-3: No Wireless Link With Proper Ethernet Connections
Access Point A WLAP RF Statistics
Current # WLAP Itf 1 Root Interface 1
Root Priority 8000 hex
Current State Functional Root MAC Addr 00:A0:F8:8B:71:45
Priority 8000 hex Root Path Cost 1
------------- Wireless AP Interface Table ---------------
Itf WLAP Itf Itf Path Designated Designated
ID MAC Addr State Cost Root ID Cost WLAP ID Itf ID
8001 00:A0:F8:8B:71:45 FWD 1 800000a0f88b7145 0 800000a0f88b7145 8001
8002 00:00:00:00:00:00 DIS 1 800000a0f893C5B5 0 800000a0f893C5B5 8002
8003 00:00:00:00:00:00 DIS 1 800000a0f893C5B5 0 800000a0f893C5B5 8003
8004 00:00:00:00:00:00 DIS 1 800000a0f893C5B5 0 800000a0f893C5B5 8004
Refresh-[F1] Timed-[F2] Previous-[F4] Exit-[ESC]
Figure 4-4: Wireless Link After Loss of Ethernet Connection

Chapter 4. Using the Link Required Option
14 Configuring Access Point Bridging and Repeating (WLAP Mode)
Access point settings for the example in Figure 4-5 are described as follows:
Basic Settings. Make the settings previously described in 1.1: Basic Settings for Access Points.
WLAP Mode on RF Configuration Screen. On designated WLAPs B and C, set the WLAP Mode to
Link Required. This causes the WLAPs to search for another access point with an Ethernet
connection in the event the root access point loses its Ethernet connection. WLAP Mode for access
points A and D is set to Enabled.
WLAP Priority on RF Configuration Screen. On access point A, make sure its WLAP Priority is set
to a lower number (e.g., 7000) than the two WLAPs. On access point D, make sure its WLAP
Priority is set to a lower number (e.g., 6000) than the other access points. The lower priority
number ensures that access point D is recognized as the new root access point in the event access
point A loses its Ethernet connection.
WLAP Manual BSS ID on RF Configuration Screen. On designated WLAPs B and C, set the
WLAP Manual BSS ID to the “preferred”MAC address of the root access point A. To enter a
preferred MAC address, change the first two numbers of the MAC address from 00 to 01; for
example, 01:A0:F8:8D:25:F2. Using a preferred MAC address not only causes WLAPs B and C to
associate with the root access point A, it also allows them to roam to another access point if the
Ethernet connection to access point A is lost.
Ethernet Timeout on System Configuration Screen. Set the Ethernet Timeout to 1 on the two
access points connected to the Ethernet (access points A and D). On WLAPs B and C, set the
Ethernet Timeout to the default value of 0. With its Timeout set to 1, access point A detects a
broken Ethernet connection and turns off its radio to allow the designated WLAPs B and C to
search for another access point (e.g., access point D). Likewise, if access point D becomes the root,
it would perform in the same way if it loses its Ethernet connection. An example System
Configuration screen is shown in Figure 4-6.
WLAP Mode = Link Required.
WLAP Priority = 8000.
WLAP Manual BSS ID set to access
point A’s preferred MAC address
(01:A0:F8:93:C5:B5).
Ethernet Timeout = 0.
A
B
WLAP Mode = Enabled.
WLAP Priority = 7000.
WLAP Manual BSS ID set to its own
MAC address (00:A0:F8:93:C5:B5).
Ethernet Timeout = 1.
Ethernet
D
If Ethernet connection is
lost, accesspointDbecomes
new root access point.
WLAP Mode = Enabled.
WLAP Priority = 6000.
WLAP Manual BSS ID set to its
own MAC address.
Ethernet Timeout = 1.
Figure 4-5: Network with Backup Root Access Point
C
FRAME