Cabletron Systems 3Com manual Filtering and Access Control

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18CHAPTER 1: OVERVIEW OF DIGITAL WIRELESS NETWORKING

Filtering and Access Control

The AP provides facilities to limit the wireless clients that associate with it and the data packets that can forward through it. Filters provide network security or improve performance by eliminating broadcast/multicast packets from the radio network.

The Access Control List (ACL) contains MAC addresses for wireless clients allowed to associate with the AP. This provides security by preventing unauthorized access.

The AP also uses a disallowed address list of destinations. This feature prevents the AP from communicating with specified destinations. This can include network devices that do not require communication with the AP or its wireless clients.

Depending on the setting, the AP can keep a list of frame types that it forwards or discards. The Type Filtering option prevents specific frames (indicated by the 16-bit DIX Ethernet Type field) from being processed by the AP. These include certain broadcast frames from devices unimportant to the wireless LAN but which utilize bandwidth. Filtering out unnecessary frames also improve throughput.

DHCP Support The AP uses Dynamic Host Configuration Protocol (DHCP) to obtain a leased IP address and network configuration information from a remote server. DHCP is based on BOOTP protocol. DHCP can coexist or interoperate with BOOTP. An AP sends out a DHCP request searching for a DHCP server to acquire the network configuration and firmware filenames. Because BOOTP and DHCP interoperate, the one that responds first becomes the server that allocates information. The DHCP client automatically sends a DHCP request to renew the IP address lease as long as the AP is running. (This parameter is programmed at the DHCP server. For example, Windows NT servers typically are set for 3 days.)

The AP can optionally download two files when a boot takes place, the firmware file and an HTML file, because firmware versions 4.00-31 and above support Web servers. Users can program the DHCP or BOOTP server to transfer these two files when a DHCP request is made.

When the AP receives a network configuration change or is not able to renew the

IP address lease the AP sends out an SNMP trap.

Media Types The AP supports bridging between Ethernet, radio, and serial media.

The Ethernet interface fully complies with Ethernet Rev. 2 and IEEE 802.3 specifications. The AP supports 10BASE-T wired connections and full-speed filtering. The data transfer rate over radio waves is 11 Mbps. The Ethernet interface is optional for single-cell or PPP-connected networks.

The radio interface conforms to IEEE 802.11B specifications. The interface operates at 11 Mbps using direct-sequence radio technology. The AP supports multiple-cell operations with fast, transparent roaming between cells. With the direct-sequence system, each cell operates independently. Each cell provides a 11 Mbps bandwidth. Adding cells to the network provides increased coverage area and total system capacity. The AP supports wireless clients operating in Power Save Polling (PSP) mode or Continuously Aware Mode (CAM) without user intervention.

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Contents AirConnect 11 Mbps Wireless LAN Access Point User Guide VersionClara, California 3Com CorporationBayfront Plaza Santa 95052-8145Contents Installing Access Point Hardware Monitoring Wireless Clients Access Point Installation Configuring the AP Access Point Specifications Technical Support Page AirConnect Network Overview of Digital Wireless NetworkingIntroduction TopologiesOverview of Digital Wireless Networking AirConnect Network Topologies Point AirConnect AccessWireless clients To the Ethernet LANAirConnect Access Point Radio Basics PowerBASE-TWireless clients and APs Results in the original digital dataRadio Basics Wireless LAN Service Area 802.1d Spanning Tree SupportSite Surveys Filtering and Access Control Network Control Protocol NCP as described PPP Connection Data Rate Requirement Overview of Digital Wireless Networking Theory of Operation Simple Network Management Protocol Snmp Management protocol MIB Using SnmpProgrammable Snmp Trap Support Increased MIB SupportUsing the User Interface Method DescriptionPackage Contents Installing Access Point HardwarePrecautions RequirementsRemote power distribution system, Part Number AP-PS-11 Power OptionsStandard power supply 115/230VAC, 50/60Hz, 24V/14 US line cord Part NumberMounting the AP BelowWall Mount To mount an AP on a wall Ceiling Mount To mount an AP on a ceiling Mounting the AP Using PowerBASE-TPowerBASE-T can be used to power the AP LED Indicators Off Blinking Power No power Power on During boot sequenceCondition, and other activity Verify AP Operation Troubleshooting3Com Support Center Electrical Management System EMS operating outletVerify Network Wiring Topology Network connection verificationPage Interface Statistics Monitoring StatisticsSystem Properties Forwarding CountsEthernet Statistics Radio FrequencyStatistics Press Esc or Previous F4 to exit MiscellaneousStatistics window, select Main Menu→Misc Statistics Type Name DefinitionClearing Statistics Known APsSelect Clear All Statistics Help File Access Gaining Access to the User Interface UI Using a Web BrowserGaining access to the User Interface UI Setup Network Web Server Help File AccessSelect Close/Exit Accessing the Web Browser UISelect Virtual Directory Select System ConfigurationSelect Special Functions Select Reset AP Select Save F1 to save the configurationUnder Configuration, select Security Select System Password Type the case sensitive AP nameSelect Easy Setup--Easy Setup Select Easy Setup--Easy Setup Click Add/Delete GatewaysParameter Description Adding Allowed Wireless Clients Adding or Deleting a Range of Allowed Wireless ClientsAdding or Deleting Disallowed Wireless Clients Enabling or Disabling Encryption For the Short RF Preamble setting, click DisabledConsiderations Select Configuration--SecurityEnable or disable interfaces on the AP Interface Description Default ConditionFrequency No. of Channels Country Enter the Multicast Mask data and voice values Select Enabled or Disable All for All Snmp Traps Snmp Trap Description Default ValueConfiguring the Originating Modem Configuring the Answering Modem Filtering to Forward PacketsFiltering to Discard Packets Disabling Type Filtering Removing Filtered Packet Types Networking ProtocolsClick Delete Filter Under Configuration, select FirmwareActive. Clear the wireless client association table for Special Function DescriptionMonitoring Wireless Clients Wireless ClientsSelect Regular at the Wireless Clients prompt Indicates a 3Com voice-enabled device Ascii Interface Latest version. Refer to Manually Updating AP Firmware onVersions Enable serial port Configure the AP for the followingArrow/Function Key Control Character To exit from submenus, press Esc Prompt DescriptionTo enable and configure the serial port connection on the AP Select Telnet LoginsPress Tab to select System Password Configuring The Serial PortHanging Up Setting DescriptionConfiguring the Dial-Up System Select Modem HangupInstallation WindowConfiguring the AP That can associate with this AP. The default is Disabled Wsaid PPP Direct Establishing a ConnectionPPP with Modems Answering AP Set the Connect Mode to AnswerOriginating AP From the answering APs UIFor automatic dial-out, reset the AP Range of Wireless Clients Press up/down arrows to toggle between range and individualRemoving Allowed Wireless Clients Enable/Disable the ACLRemoving All Allowed Wireless Clients Removing Disallowed Wireless Clients Load ACL from Wireless Client ListAdding Disallowed Wireless Clients Address FilteringClients from the AP Clearing WirelessSetting Logging OptionsManually Updating AP FirmwarePrevious version of AP firmware Remainder of this procedure uses Windows 98 as an example Select Alter Filenames/HELP URL/TFTP and press EnterType the firmware file name in the Download Filename field Open the Special Functions window Select Transfer from the emulation program menu barSelect Send File Download is complete when the UI displays Select Alter Filenames/HELP URL/TFTP Server and press EnterPerforming Pings Using MD5Authentication Extended RoamingWireless client and the access point EncryptionHex-digit sequence Press the Tab key to highlight .Short RF Preamble Enabled Restoring ConfigurationsSelect Restore Factory Configuration Radio Characteristics Frequency No. of Channels Country Access Point SpecificationsPhysical Characteristics Output CharacteristicsNetwork Characteristics Online Technical ServicesTechnical Support World Wide Web SiteLatin America North AmericaTo obtain an RMA number, call or fax Page Index AsciiSnmp agent 3Com Corporation Limited Warranty 3Com AirConnect Access PointObtaining Warranty Regulatory Compliance Information Radio Frequency Interference Requirements CanadaImportant Read Before Using This Product 3Com End User Software License Agreement
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