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ZyXEL Communications B-420 Wireless LAN, 4.1Wireless LAN Basis, 4.1.1 Channel, 4.1.2 ESS ID, 4.1.3 WEP Encryption, 4.1.4 RTS/CTS

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ZyAIR B-420 Wireless LAN Ethernet Adapter and Bridge

Chapter 4

Wireless LAN

This chapter discusses how to configure Wireless LAN screens on the ZyAIR.

4.1Wireless LAN Basis

This section provides basic background information on the wireless LAN screens.

4.1.1 Channel

The range of radio frequencies used by IEEE 802.11b wireless devices is called a “channel”. Channels available depend on your geographical area. You may have a choice of channels (for your region) so you should use a different channel than an adjacent AP (access point) to reduce interference. Interference occurs when radio signals from different access points overlap causing interference and degrading performance.

Adjacent channels partially overlap however. To avoid interference due to overlap, your ZyAIR should be on a channel at least five channels away from a channel that an adjacent AP is using. For example, if your region has 11 channels and an adjacent AP is using channel 1, then you need to select a channel between 6 or 11.

The ZyAIR’s “Scan” function is especially designed to automatically scan for a channel with the least interference.

4.1.2 ESS ID

An Extended Service Set (ESS) is a group of access points connected to a wired LAN on the same subnet. An ESS ID uniquely identifies each set. All access points and their associated wireless stations in the same set must have the same ESSID.

4.1.3 WEP Encryption

WEP (Wired Equivalent Privacy) encrypts data frames before transmitting over the wireless network. WEP encryption scrambles the data transmitted between the wireless stations and the access points to keep network communications private. It encrypts unicast and multicast communications in a network. Both the wireless stations and the access points must use the same WEP key for data encryption and decryption.

4.1.4 RTS/CTS

A hidden node occurs when two stations are within range of the same access point, but are not within range of each other. The following figure illustrates a hidden node. Both stations (STA) are within range of the access point (AP) or wireless gateway, but out-of-range of each other, so they cannot “hear” each other, that

Wireless LAN

4-1

Contents

User's Guide Copyright Federal Communications Commission (FCC) Interference Statement ZyXEL Limited Warranty Customer Support Table of Contents Chapter 5 IP Screen LOGS Chapter 6 Logs Screens Chapter 7 Maintenance Chapter 8 Introducing the SMT Chapter 12 System Information Chapter 13 Firmware and Configuration File Maintenance APPENDICES A-1 B-1 List of Figures Page Page List of Tables Preface User Guide Feedback Part I: OVERVIEW Page Getting to Know Your ZyAIR 1.1Introducing the ZyAIR 1.2ZyAIR Features 10/100M Auto-negotiatingEthernet/Fast Ethernet Interface 10/100M Auto-crossoverEthernet/Fast Ethernet Interface Bridge Power over Ethernet (PoE) 802.11b Wireless LAN Standard Output Power Management WDS Functionality Brute-ForcePassword Guessing Protection SNMP Full Network Management 1.3Applications for the ZyAIR 1.3.1 Infrastructure 1.3.2 Ad Hoc 1.3.3 Bridge Page Introducing the Web Configurator 2.1Accessing the ZyAIR Web Configurator 2.2Navigating the ZyAIR Web Configurator 2.3Resetting the ZyAIR 2.3.1 Method of Restoring Factory-Defaults Part II: SYSTEM, WIRELESS AND IP Page System Screens 3.1System Overview 3.2Configuring General Setup 3.3Configuring Password 3.4Configuring Time Setting Figure 3-3Time Setting Table 3-3Time Setting Wireless LAN 4.1Wireless LAN Basis 4.1.1 Channel 4.1.2 ESS ID 4.1.3 WEP Encryption Page 4.1.5 Fragmentation Threshold 4.2Wireless Security Overview 4.3WEP Overview 4.3.1 Data Encryption 4.3.2 Authentication 4.4Configuring Wireless 4.4.1 Infrastructure Roaming Figure 4-6Wireless : Infrastructure Table 4-1Wireless : Infrastructure 4.4.2 Ad-Hoc Figure 4-7 Ad-hoc(IBSS) Wireless LAN Figure 4-8Wireless : Ad Hoc 4.4.3 Bridge Figure 4-10Bridge Loop: Two Bridges Connected to Hub Figure 4-11Bridge Loop: Bridge Connected to Wired LAN Figure 4-12Wireless : Bridge Table 4-3Wireless : Bridge Page Page IP Screen 5.1Factory Ethernet Defaults 5.2TCP/IP Parameters 5.2.1 IP Address and Subnet Mask 5.3Configuring IP Table 5-2IP You must know the IP address assigned to the ZyAIR (by the DHCP server) to access the ZyAIR again If you change the ZyAIR's IP address, you must use the new IP address if you want to access the web Part III: LOGS Logs Screens 6.1Configuring View Log 6.2Configuring Log Settings Figure 6-2Log Settings Table 6-2Log Settings Page Page Part IV: MAINTENANCE Page Maintenance 7.1Maintenance Overview 7.2System Status Screen 7.2.1 System Statistics 7.3Wireless Screen Figure 7-3Channel Usage Table 7-3Channel Usage 7.4F/W Upload Screen Table 7-4Firmware Upload WARNING Firmware Upload in Process Figure 7-5Firmware Upload In Process 7.5Configuration Screen 7.5.1 Backup Configuration 7.5.2 Restore Configuration Table 7-5Restore Configuration Do not turn off the device while configuration file upload is in progress Figure 7-10Configuration Upload Successful Figure 7-11Network Temporarily Disconnected 7.5.3 Back to Factory Defaults Figure 7-14Reset Warning Message Part V: SMT CONFIGURATION Page Introducing the SMT 8.1Connect to your ZyAIR Using Telnet 8.2Changing the System Password 8.3ZyAIR SMT Menu Overview Example Figure 8-3ZyAIR B-420SMT Menu Overview Example 8.4Navigating the SMT Interface 8.4.1 System Management Terminal Interface Summary Page General Setup 9.1General Setup 9.1.1 Procedure To Configure Menu Table 9-1Menu 1 General Setup LAN Setup 10.1 LAN Setup 10.2 TCP/IP Ethernet Setup 10.3 Wireless LAN Setup Figure 10-3Menu 3.5 Wireless LAN Setup Table 10-2Menu 3.5 Wireless LAN Setup Page 10.3.1 Configuring Bridge Link Table 10-3Menu 3.5.4 Bridge Link Configuration SNMP Configuration 11.1 About SNMP 11.2 Supported MIBs 11.3 SNMP Configuration 11.4 SNMP Traps Table 11-2SNMP Traps Table 11-3Ports and Interface Types System Information 12.1 System Status Figure 12-2Menu 24.1 System Maintenance : Status Table 12-1Menu 24.1 System Maintenance : Status 12.2 System Information 12.2.1 System Information 12.2.2 Console Port Speed 12.3 Log and Trace 12.3.1 Viewing Error Log Page Firmware and Configuration File Maintenance 13.1 Filename Conventions 13.2 Backup Configuration 13.2.1 Backup Configuration Using FTP 13.2.2 Using the FTP command from the DOS Prompt 13.2.3 Backup Configuration Using TFTP 13.2.4 Example: TFTP Command 13.3 Restore Configuration 13.4 Uploading Firmware and Configuration Files 13.4.1 Firmware Upload 13.4.2 Configuration File Upload 13.4.3 Using the FTP command from the DOS Prompt Example 13.4.4 TFTP File Upload 13.4.5 Example: TFTP Command System Maintenance and Information 14.1 Command Interpreter Mode 14.2 Time and Date Setting Part VI: APPENDICES Page Troubleshooting Problems Starting Up the ZyAIR Problems with the Password Problems Communicating with Other Computers Appendix B Brute-ForcePassword Guessing Protection Chart B-1 Brute-ForcePassword Guessing Protection Commands Page Setting up Your Computer’s IP Address Windows 95/98/Me Properties Page Windows 2000/NT/XP Page Page Page Macintosh OS 8/9 Page Macintosh OS Page Page Wireless LAN and IEEE Benefits of a Wireless LAN IEEE Ad-hocWireless LAN Configuration Infrastructure Wireless LAN Configuration Diagram D-2ESS Provides Campus-WideCoverage Page Antenna Selection and Positioning Recommendation Antenna Characteristics Frequency Radiation Pattern Antenna Gain Connector Type Power over Ethernet Specifications Page IP Subnetting IP Addressing IP Classes Subnet Masks Subnetting Example: Two Subnets Page Example: Four Subnets Example Eight Subnets Subnetting With Class A and Class B Networks Page Command Interpreter Command Syntax Command Usage Page Log Descriptions Page Log Commands Log Command Example Power Adaptor Specifications Page Index