Nokia A032 Bedienungsanleitung

Wireless LAN Access P oint Addendum[...]

ii Nokia A032 Addendum Copyright notices Copyright © Nokia Networks 2001. All rights reserved. Nokia is a registered trademark of Nokia Corporation, Finland. Windows 95, Windows 98, Windows 2000 and Windows NT are registered trademarks of Microsoft Corporation. MS-DOS is a registered trademark of Microsoft Corporation. Other products may be tradem[...]

Contents iii T able of content s Copyright notices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii Introduction 5 Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Access point parameters 7 Table o[...]

iv Nokia A032 Addendum[...]

Introduction 5 1. Introduction Purpose This document has been written to serve as an addendum to the existing A032 user manuals. It does not attempt to replace any existing user manual, and is focussed on correcting errors and omissions from those manuals, and documenting features added in recent firmware updates. Scope This document describes the [...]

6 Nokia A032 Addendum Terms, acronyms and abbreviations Term Meaning WLAN Wireless LAN IEEE 802.11 AP Access Point NAS Network Access Server UDP User-Datagram-Protocol RFC Request For Comments MT Mobile Terminal (WLAN client) LAN Local Area Network WEP Wire-Equivalent Privacy WLAN Wireless LAN IEEE 802.11[...]

Access point parameters 7 2. Access point parameters This section describes the changes to AP parameters, and the use of newly added parameters. Table of parameters Refer to the A032 user guide for descriptions of how to use the management interfaces. Name (command line) Config Web page Factory default Valid range Description channel Access Point R[...]

8 Nokia A032 Addendum beacon_interval n/a 100 1–65535 Beacon interval in mS dtim_interval n/a 5 1–255 Number of beacons between DTIMs tx_power n/a “high” “low”, “low1”, “low2”, “high” Access points transmit power level. By default, this is set to maximum, but may be reduced to suit applications with multiple APs. cca_mode n/[...]

Access point parameters 9 wep_mode WEP Advanced WEP “wep” This parameter determines the authentication policy of the AP: “open” Accept either WEP or open system “wep” MUST use WEP “wifi” Relaxed form of WEP setting allowing use of shared keys with open system authentication “personal” MUST use specific key WEP (default key not a[...]

10 Nokia A032 Addendum wep_key WEP none 1–4, hex string Set default key 1–4 to the value hex string . Hex string is from 10 to 32 characters in length, according to the strength of wep key being entered. Web interface also allows keys to be entered in ASCII. radius_server Advanced WEP none 1–2, IP address IP address of primary (1) and seconda[...]

Access point parameters 11 zone_privacy Advanced Access Point “off” “on” or “off” If set to “on”, the AP blocks traffic from being passed directly between radio clients (this has the effect of blocking peer-peer networking) snmp_contact SNMP “Contact” up to 32 characters SNMP contact name (from the RFC1213 MIB) snmp_sys_name SNM[...]

12 Nokia A032 Addendum Radio parameters A number of new radio parameters have been added for the AP. As with all AP radio settings, they are only accessible via the command line interface. The new parameters and their functions are described in the following subsections. Path delay This parameter is designed for use on systems where an AP is being [...]

Access point parameters 13 Beacon interval Sets the time interval between beacons in milliseconds. This defaults to 100ms – longer intervals reduce the amount of idle load on the radio interface, but may increase the time taken to join a network or roam. The beacon interval can be changed with the command set beacon_interval < n > DTIM inte[...]

14 Nokia A032 Addendum CCA mode This setting determines which CCA mode should be used. The modes are: Use caution when altering this setting, as an inappropriate CCA mode can prevent reliable reception. The default setting is to use Carrier sense only – this can be changed with the command set cca_mode < New_Mode > ED Threshold This value c[...]

Access point parameters 15 ED Absolute If set, this variable causes the ED threshold set by ‘set ed_threshold’ to be regarded as an absolute value. Otherwise the value is taken to be relative to the noise floor. Use caution when altering this setting, as in combination with certain CCA modes it can prevent reliable reception. By default, ED abs[...]

16 Nokia A032 Addendum 3. Minor functional changes Learn mode In this mode, only one of the interfaces is operational (either LAN or radio) – if the unit is started up with both a radio card and LAN connection, then the active interface will be radio, and the LAN connection ignored; otherwise, the connected interface will be used. In LAN learn mo[...]

Minor functional changes 17 SNMP changes The A032 enterprise traps have been updated since the previous issue of the user manual. The following are now generated: Trap Name Description 1 A032 Authenticate fail Generated in the event that a station tries to associate but is refused due to the fact that the NID Name security feature is enabled. Note [...]

18 Nokia A032 Addendum WEP key lengths The A032 now has explicit support for 104 bit WEP keys. Some manufacturers have produced 802.11b clients using 104-bit WEP keys (usually marketed as being 128 bit). Creating a 104-bit key in the A032 should allow these clients to be used with their maximum key strength.[...]

Radius operation 19 4. Radius operation Introduction This section describes the Nokia Radius client implementation. It provides sufficient detail to get third-party Radius servers to operate with the A032 Access Point. It describes frame formats and details of interactions between the AP and a Radius server. It does not cover how a particular Radiu[...]

20 Nokia A032 Addendum Technical information Radius overview Radius is a simple authentication protocol for remote clients. The name Radius comes from the words Remote Authentication Dial In User Service. The Radius protocol has traditionally been used in modem pools but nowadays its use has been expanded to include firewall authentication, amongst[...]

Radius operation 21 The traditional Radius system is meant to operate within a secure network, such as intranet, because it does not require much skill to capture radius packets and use faked packets to provide false authentication information. That’s why the WEP keys received from Radius server are encrypted. Radius security scheme has three to [...]

22 Nokia A032 Addendum on the protocol specification. The protocol specification uses name Network Access Server (NAS) for the client of the Radius server. On our WLAN radius security scheme, the AP is equivalent to the NAS on the protocol specification so the AP is a client of the Radius server (in other words, the NAS functionality is build into [...]

Radius operation 23 Radius operation The use of a Radius server on the current AP range can be enabled using the web pages or via the command line, either through the serial port or via Telnet. Once enabled, whenever a wireless station attempts to authenticate with the AP, the following interaction with the Radius server occurs: The basic message f[...]

24 Nokia A032 Addendum The authentication procedure is initiated by the station, which sends Authentication Req MAC frame to the AP. The AP builds a Radius Access- Request containing a Radius user-name and user-password derived as follows: • The user-name is either the MAC address of the station expressed as a 12-character hexadecimal string or t[...]

Radius operation 25 the AP. If a WEP key has been stored in the Radius database for this station, it uses the Blowfish algorithm to encrypt the WEP key and includes this as a Vendor-Specific Radius attribute. Otherwise, no Vendor-Specific attribute is included. The WEP key is transmitted as a 32-character hexadecimal ASCII string derived as follows[...]

26 Nokia A032 Addendum The encrypted WEP key is placed in the String field. This is formatted also like an attribute (type+length+string) but the type values are defined in this document. There are two formats for the Nokia-specific attribute: The format above has no mechanism for determining the length of the WEP key. The first implementation of t[...]

Radius operation 27 This uses a new type code and the attribute now contains the length of the WEP key in bytes expressed as a 2-character ASCII hex string in the range 05 to 10. When configuring a Radius server, the two strings shown above can be treated as a single 34-character hex string. When AP receives the Access-Accept message, if a vendor-s[...]

28 Nokia A032 Addendum Configuration To configure the A032 to use Radius authentication, carry out the following steps (the items within <> are user-specified, the other text must be typed as shown): 1 Set the Radius secret and the password common to all APs: set shared_secret < shared_secret > < password > 2 Set the IP addresses [...]

Radius operation 29 Because there are many different radius servers available, no specific configuration details can be given. However, the following general procedure can be used: 1 Set the Radius secret and the password common to all APs: set shared_secret < shared_secret > < password > 2 For each station, create an entry where the us[...]

30 Nokia A032 Addendum 5. DHCP operation Introduction This document describes the operation and configuration of DHCP on the AP. Server operation is essentially unchanged, other than the effects of revisions to the user interface to cater for client operation. The AP can be configured for either server or client operation (this is an exclusive choi[...]

DHCP operation 31 Server operation The Server implementation is targeted at small installations (such as home use), and includes only a minimal feature set. It is anticipated that larger networks would have a pre-existing system administration policy – either precluding the use of DHCP, or having a more fully featured DHCP server under central co[...]

32 Nokia A032 Addendum • If the AP does not have a fixed IP address assigned to it, then it will claim one from the DHCP address pool during startup. • If the AP is put into radio learn mode, the DHCP server is automatically enabled, using either the default pool address or (if present) its own IP address as the pool base address. • The DHCP [...]

DHCP operation 33 Client operation The DHCP client has been designed to ease integration of the AP into larger networks, and as such has a larger feature set than the server. The intention is to allow the DHCP protocol to be used to download a working configuration, enabling the management of all APs on a network to be handled centrally. In order t[...]

34 Nokia A032 Addendum Operational sequence When the DHCP client is enabled, the AP will first boot up into a limited operation mode, connected to LAN only, and begin the DHCP negotiation. During this phase, the AP will signal no radio operation on the LEDs. Only when a DHCP offer is received (and accepted), or the process is abandoned (no response[...]

DHCP operation 35 • DHCP response with no option string – AP will operate using its stored configuration, but with the IP address provided by DHCP. • DHCP response with option string and/or a configuration file reference – AP will accept the parameters given, and fill in the remainder from its stored configuration. The AP gives precedence t[...]

36 Nokia A032 Addendum If a DHCP frame is received containing a file reference, the AP will use TFTP to download and store it. See page 42 for details of the TFTP download, but note that, in this case, there is a hierarchy of configuration data: 1 The standard DHCP options (IP address and network parameters, including host (AP) name) are fetched an[...]

DHCP operation 37 Accepting dynamic IP addresses Using a DHCP client implementation allows the AP to be offered an IP address according to one of the following schemes: • Automatic addressing – the server allocates the address, but offers it indefinitely. • Dynamic addressing – the server allocates an address for a time-limited period. • [...]

38 Nokia A032 Addendum DHCP standard options The following tables list AP parameters and their availability via DHCP. These are the standard DHCP options and their option codes: Parameter DHCP option code Default value Default gateway 3 none Subnet mask 1 255.0.0.0 IP address n/a none AP name 12 “LocalAP”[...]

DHCP operation 39 DHCP Vendor class options All other AP configuration items require private option codes for vendor-specific option processing. These are packaged into DHCP option 43, using the encapsulated option format described there. The following table lists the remaining AP configuration items and their option code and format within DHCP. Op[...]

40 Nokia A032 Addendum Long retry 22 1 15 value Telnet port 30 2 23 value (2 octets) HTTP port 31 2 80 value (2 octets) Protocol filter 32 1 0 1 (discard all non-TCP/ IP frames) or 0 (no filtering) Management access 40 max. 8 “any” ASCII text: “any”, “specific” or “none” Manager IP list 41 max 16 none between 1 and 4 IP addresses WE[...]

DHCP operation 41 The AP requests this parameter list by sending a Vendor class identifier (DHCP option) with the DHCPREQUEST/DISCOVER frames. This will comprise the option code (60), length (10), and the ASCII text “Nokia A03x”. The AP does not expect to receive values for every parameter in the table above; they are subject to the same princi[...]

42 Nokia A032 Addendum TFTP download DHCP may also be used to notify the AP of a filename to use for a download. The AP will parse this, if present, and use TFTP to request the file specified. This file is structured like a normal AP TFTP config.txt file (although it may optionally be augmented with WEP keys and passwords, and should not contain pa[...]

DHCP operation 43 DHCP Web pages DHCP configuration page The configuration page simply displays (and allows changes to) the five DHCP configuration entries.[...]

44 Nokia A032 Addendum DHCP status page (server) DHCP status page (client)[...]

TFTP config.txt file 45 6. TFTP config.txt file The TFTP config.txt file has been restructured in line with the changes to configuration. The following example illustrates the current format: /Config.txt for AP(Example) on Wed, 27 Jun 2001 09:55:06 %channel: 11 %net_name: "ExampleNet" /*%rts_threshold: 2301 /*%frag_threshold: 2346 /*%shor[...]

46 Nokia A032 Addendum /*%nat_port: off %community_get: "public" %community_set: "private" /*%radius_server: 1 0.0.0.0 /*%radius_server: 2 0.0.0.0 %snmp_contact: "Contact" %snmp_sys_name: "Sys Name" %snmp_location: "Location" %path_delay: 0 %zone_privacy: off %beacon_interval: 100 %dtim_interval: 5 [...]