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| Newer page: | version 3 | Last edited on Tuesday, October 26, 2004 4:56:36 pm | by AristotlePagaltzis | Revert |
| Older page: | version 2 | Last edited on Friday, June 7, 2002 1:07:50 am | by perry | Revert |
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-
-
-
-Wireless-HOWTO
-
-
-
-----
-
-!!!Wireless Howto
-
-!!Roberto Arcomano berto@fatamorgana.comv1.5 - June 2, 2002
-
-
-----
-''Wireless is a new technology in networking cards, with high speed rate
-(up to 11 Mbps). This document explains how to setup Wireless in Linux, compatibility
-problems, something about geographic requirements and more. Latest release
-of this document can be found at
-http://www.fatamorgana.com/bertolinux''
-----
-
-
-
-
-!!1. Introduction
-
-
-****1.1 Introduction
-
-****1.2 Copyright
-
-****1.3 Translations
-
-****1.4 Credits
-
-
-
-
-
-!!2. Background Knowledge
-
-
-****2.1 What about Wireless?
-
-****2.2 What's the max distance between radio cards?
-
-****2.3 What's the difference between wired and Wireless network?
-
-****2.4 What I need to know to setup a Wireless network?
-
-****2.5 Why should I setup a Wireless network and what I expect from it?
-
-****2.6 What Wireless cards are covered by this howto?
-
-****2.7 How much do they cost?
-
-
-
-
-
-!!3. Technical info about Wireless
-
-
-****3.1 Physical Layer
-
-****3.2 Configurations
-
-****3.3 Compatibility
-
-****3.4 Should I use Adhoc or Infrastructure?
-
-****3.5 A Linux Box cannot act as an !AccessPoint?
-
-
-
-
-
-!!4. Toolbox required
-
-
-****4.1 Hardware requirement
-
-****4.2 Software requirement
-
-
-
-
-
-!!5. Overview on Wireless network setup.
-
-
-****5.1 Fundamental steps
-
-****5.2 Low Level Kernel Config
-
-****5.3 Data-link level setting
-
-****5.4 Ip setting
-
-
-
-
-
-!!6. Setup
-
-
-****6.1 General setup info
-
-****6.2 Proxim Symphony
-
-****6.3 Webgear Aviator 2.4 and !AviatorPro
-
-****6.4 Lucent Wavelan I, II, Orinoco products and Cabletron
-
-****6.5 YDI
-
-
-
-
-
-!!7. More about Wireless
-
-
-****7.1 A Wireless Linux distribution
-
-
-
-
-
-!!8. Useful links
-
-
-****8.1 Open software link
-
-****8.2 Commercial link
-
-
-
-
-
-!!9. FAQ - Frequently asked questions
-
-
-
-
-!!10. Appendix A - Netmask 255.255.255.255, proxy arp and bridging
-
-
-
-
-!!11. Appendix B - Siemens DECT Radio Modem
-----
-
-!!1. Introduction
-
-!!1.1 Introduction
-
-
-
-This document explains something about Wireless networking, how to setup
-it, problems with it. Unliked wired network, Wireless requires some additional
-trick to work well. You should know something about antennas, pointing it,
-roaming info and so on. Feedback are welcome. You can found more interesting
-help at
-Jean Tourrilhes Wireless Howto
-
-For any suggestion and feedback write to my
-email address
-!!1.2 Copyright
-
-
-
-Copyright (C) 2000,2001 Roberto Arcomano.
-
-
-This document is free; you can redistribute it and/or modify it under the
-terms of the GNU General Public License as published by the Free Software Foundation;
-either version 2 of the License, or (at your option) any later version.
-
-
-This document is distributed in the hope that it will be useful, but WITHOUT
-ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
-FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
-You can get a copy of the GNU GPL
-
-!!1.3 Translations
-
-
-
-If you want to translate this document you are free, you only have to:
-
-
-
-
-
-
-
-
-***#Check that another version of it doesn't already exist at your local LDP
-***#
-
-***#Maintain all 'Introduction' section (including 'Introduction', 'Copyright',
-'Translations', 'Credits').
-***#
-
-
-
-Warning! You don't have to translate TXT or HTML file, you have to modify
-LYX or SGML file, so that it is possible to convert it all other formats (TXT,
-HTML, RIFF, etc.).
-
-
-No need to ask me to translate! You just have to let me know (if you want)
-about your translation.
-
-
-Thank you for your translation!
-
-!!1.4 Credits
-
-
-
-Thanks to
-Fatamorgana Computers for hardware equipment and experimental opportunity.
-
-
-Thanks to
-Linux Documentation Project for publishing and uploading my document in a very quickly fashion.
-----
-
-!!2. Background Knowledge
-
-!!2.1 What about Wireless?
-
-
-
-Wireless is a new technology that can help you to connect computers at
-distance. It works with Wireless cards with a TX/RX inside at 2.4 GHz while
-the software interface is Ethernet-like, with an hardware address different
-for each card in the world. Typical transmit power is 10-20 mW till 100mW (see
-standard IEEE 802.11 and FCC/CEPT licenses).
-
-!!2.2 What's the max distance between radio cards?
-
-
-
-The most important thing in Wireless communications is the line of sight
-clear: you MUST SEE (with eyes or with a binocular) the antenna from the other
-end or you can have (at most) a little tree between them.
-
-
-The distance depends on the antenna and (eventually amplifier) used: 2-300
-meters with a omnidirectional antenna; 1 km with a directive one; 2-3 km with
-a omnidirectional amplified (200mW); some km with parabolic antenna. 50-60
-km with parabolic or directive antenna amplified (some Watts).
-
-
-Be aware that it is not always legal to amplifier Wireless cards, cause
-you could violate FCC/CEPT (and also your country relative) specifics.
-
-!!2.3 What's the difference between wired and Wireless network?
-
-
-
-Wired networks are very simple to setup (at least at low level). Wireless
-networks are very difficult to setup, to manage, to debug... Typical problem
-with wired networks like hardware install, software install, debug and so on
-become very critical with Wireless:
-
-
-
-
-
-***#You have to choose the right Wireless card: there are many cards from many
-vendor with many requirement and specs. If you want to create a little LAN/WAN
-you have to buy IEEE 802.11 compliant Wireless cards with an Access Point.
-
-***#
-
-***#Many cards are PCMCIA, so you have to install pcmcia Linux source first.
-
-***#
-
-***#You have to test it with 2 running systems, first at very short distance,
-then you can get far.
-***#
-
-***#You should test it at any weather (typically rain).
-***#
-
-***#Finally be happy for setting up.
-***#
-
-
-
-If you installed a repeater (Linux box that has many Wireless and wired
-cards) you may have problem editing its configuration at distance!
-
-!!2.4 What I need to know to setup a Wireless network?
-
-
-
-There are a number of requirement to setup a Wireless network;
-
-
-
-
-software requirement:
-
-
-
-
-
-
-***#Generic network knowledge like IP address, netmask, routing... covered
-by generic Linux NET3-4-HOWTO; *
-***#
-
-***#Specific network knowledge like proxy arp, bridging, proc fs, contained
-in Proxy-ARP-Subnet, Bridge Mini-Howto and in Linux Kernel Source (2.2.x or
-2.4.x) under Documentation/networking/ ip-sysctl.txt) *
-***#
-
-***#Wireless network knowledge like access mode (ADHOC, INFRASTRUCTURE and
-ACCESS POINT), channel concept, outdoor and indoor defines and so on that you
-can find in any document concerning Wireless: IEEE standard 802.11, CEPT, etc.
-
-***#
-
-
-
-
-
-non software requirement:
-
-
-
-
-
-
-***#Minimal experience in antennas, physical mounting, pointing
-***#
-
-***#Pc hardware installation with particular attention to not produce interference
-between different Wireless Cards (if required).
-***#
-
-
-
-finally a great luck!
-
-
-* All Howtos needed by this document can be retrieved from
-http://www.linuxdoc.org
-!!2.5 Why should I setup a Wireless network and what I expect from it?
-
-
-
-Why? Because you're not satisfied of wired network!
-
-
-With Wireless cards you can go across garden, parks, houses, (but you MUST
-SEE the other end!).
-
-
-High Level Protocol used in Wireless Cards are the same used in Ethernet
-cards: TCP/IP over Wireless Ethernet-like but make attention to Windows Sharing
-Application, cause if you use Linux to forward, you are warned that a ip forwarder
-doesn't let pass through broadcast messages (see more on NetBIOS protocol):
-in this case you should use a WINS server to support Network Browsing (see
-Samba doc).
-
-
-Wireless let you create a little LAN/WAN with a central point of access
-(maybe with Internet Access!) and give access to anyone by air!
-
-
-Imagine a country all cabled by radio machines.
-
-
-Imagine a network that can connect all country people together, sharing
-files, audio applications, video applications at high bandwidth (like cable
-network).
-
-
-All that can be done (and it's already done in some country) using Wireless
-cards with Wireless Access Point and Wireless Linux Boxes that can operate
-as repeater (at IP level such as router or, if you want, at data-link level,
-with bridge driver, see more at
-Bridge Http Link or
-Bridge Ftp Link
-!!2.6 What Wireless cards are covered by this howto?
-
-
-
-In this howto I start with a generic configuration (to introduce Wireless
-networking), then I describe an example for each card I knew directly, with
-some trick you can use to improve its performance.
-
-
-
-
-Wireless Card list:
-
-
-
-
-
-
-***#Proxim Symphony -
-http://www.proxim.com
-***#
-
-***#Webgear AviatorPRO 2.4 (pcmcia support needed) -
-http://www.webgear.com
-***#
-
-***#Lucent Wavelan I, II, Orinoco -
-http://www.lucent.com and
-http://www.orinocowireless.com
-***#
-
-***#Cabletron -
-http://www.cabletron.com
-***#
-
-***#YDI am930_isa -
-http://www.ydi.com
-***#
-
-***#Siemens Radio Modem (Dect) -
-http://www.siemens.com
-***#
-
-***#!RadioLan (5 GHZ) -
-http://www.radiolan.com
-***#
-
-
-
-For a very more exhaustive list see
-Jean Tourrilhes Wireless Howto.
-
-
-Siemens Radio Modem is not a really 802.11 Wireless card, they are modems
-that you can attach to serial and they act as modem (at 1800 MHz, so DECT technology).
-Appendix B describe their use.
-
-
-!RadioLan cards work at 5.4GHz in a Windows 9x environment and with a !RadioLan
-Access Point that bridges between Wired and Wireless networks (there are no
-Linux driver as I know).
-
-!!2.7 How much do they cost?
-
-
-
-Wireless cards listed above are very low expansive: they start from very
-few hundred of dollars up to some thousand of dollars for Access Point that
-have 2 Wireless card (Lucent, for example) that can act as a bridge.
-----
-
-!!3. Technical info about Wireless
-
-
-Here I report some technical info to understand basic Wireless environment.
-
-
-
-
-!!3.1 Physical Layer
-
-
-
-At first layer ISO/OSI we can have 3 kind of spec:
-
-
-
-
-
-***#FHSS, Frequency Hopping Spread Spectrum
-***#
-
-***#DSSS, Direct Sequence Spread Spectrum
-***#
-
-***#Infrared connections, not covered by this howto
-***#
-
-
-!!3.2 Configurations
-
-
-
-2 types of configurations:
-
-
-
-
-
-***#!AdHoc mode (also called Independent mode), where you have independent networks
-with a BSS (Basic Service Set) each one. Each station has the same BSS.
-***#
-
-***#Infrastructure mode, where a number of networks (with a BSS each one) can
-communicate each other by means of an Access Point (one for each BSS) to create
-a ESS (Extended Service Set). Also there is a roaming function letting a station
-"attach" to the nearer Access Point.
-***#
-
-
-
-Adhoc is the simpler method (and the also the less scalable) and let many
-hosts communicate each other directly. The restrictive requirement is that
-all one are to be visible directly to reach a complete coverage of the network.
-(at least Ideally, because this problem could be solved at IP level! For more
-see Par 5.4).
-
-
-
-
-Adhoc mode
-A - - - - - C
-\ /
-| \ / |
-/\
-| / \ |
-/ \
-B - - - - - D
-
-
-
-In a Infrastructure environment you use the Access Point to which ALL other
-hosts must connect to share the network.
-
-
-
-
-Infrastructure mode
-ESS
-A - - - | - Access Point - - Access Point - | - - - D
-B - - - | BSS1 BSS2 | - - - E
-C - - - | | - - - F
-
-
-
-B and C could not see D,E and F, but they can communicate as well cause
-all one are using the same ESS. Important: A,B and C could also not see each
-other.
-
-
-In addition there are terms like indoor and outdoor to distinguish short
-area coverage from long area coverage.
-
-!!3.3 Compatibility
-
-
-
-Keep on mind that there are a number of Wireless cards in the world, but
-not every card can communicate with every other one. For talking together the
-cards have to use to:
-
-
-
-
-
-***#same configuration mode: all Adhoc or all Infrastructure
-***#
-
-***#same physical layer: all DSSS or all FHSS
-***#
-
-***#same protocol (for example Proxim has its particular proprietary protocol
-!OpenAir that cannot talk with other FHSS cards).
-***#
-
-
-!!3.4 Should I use Adhoc or Infrastructure?
-
-
-
-Access Point are very useful and killing problem but they are expansive.
-Ideally, for a more concentrated network you could use Infrastructure mode,
-while for few hosts you can choose Adhoc: why to spend much money for few hosts?
-
-
-
-
-
-Anyway be aware that if you spend much money probably all works well while
-spending less you could have some trouble.
-
-!!3.5 A Linux Box cannot act as an !AccessPoint?
-
-
-
-Good asking!
-
-
-Recently there is a kind of hardware that allows this feature: Prism2
-
-
-You can find something at
-----
-
-!!4. Toolbox required
-
-!!4.1 Hardware requirement
-
-
-
-You need a Linux Box (486 or, better, a Pentium 100+ with 16MB+ ram), the
-Wireless network card, an antenna (see par 2.2). You need the same on the other
-end (with Win9x or WinNT, if you prefer...) cause you have to simulate a communication!
-
-!!4.2 Software requirement
-
-
-
-You need:
-
-
-
-
-
-***#recent stable kernel sources (2.2.x)
-***#
-
-***#recent stable pcmcia sources (pcmcia-cs) if you bought a pcmcia card
-***#
-
-***#Wireless network driver: if you don't have it you can download it from
-the vendor web site or the card manufacturer web site. If you don't find it
-you can search at
-Jean Tourrilhes Wireless Howto.
-***#
-
-
-
-If you don't find even here you probably have to wait or to convert a Windows
-driver to a Linux driver!! (good luck!).
-
-
-After that, you have to recompile your kernel, recompile your pcmcia source
-(if need by the Wireless card), finally recompile your Wireless driver. That
-is the generic situation, maybe for some card you have to perform step 3 only
-or 1 and 3, it depends on specific driver.
-----
-
-!!5. Overview on Wireless network setup.
-
-!!5.1 Fundamental steps
-
-
-
-Once you have got the needed material and you have compiled all the needed
-you should do the fundamental step in a Wireless configuration:
-
-
-
-
-
-***#Low level kernel config Let the Linux Kernel see your Wireless card (at
-low level, such as ioport, interrupts, dma...): you must see some kind of kernel
-message that advertise you that Wireless card has been right found and configured.
-
-***#
-
-***#Data-link level setting For each particular Wireless card there is an utility
-that can set typical Wireless data-link level value. For example in Proxim
-Symphony the utility is called "rl2cfg" while in pcmcia cards settings
-are in pcmcia config files. You have to set all your Wireless cards with coherence
-to make them talk together.
-***#
-
-***#Ip setting Now you should be able to use ifconfig and route capabilities
-to change IP settings.
-***#
-
-***#Tricks for better performance and to a avoiding conflicts. Now your Wireless
-Network is basically working: in addition you have to adjust some particular
-setting like proxy-arp, icmp echo redirect, bridging, channel change and so
-on to optimize your network and avoiding strange and bandwidth killing conflicts
-
-***#
-
-
-
-N.B.: step 1, 2 and 3 correspond to level 1, 2 and 3 of standard ISO/OSI,
-while step 4 is an addendum to solve situation generated by netmask 255.255.255.255.
-In fact 32 bit netmask violates standard ISO/OSI cause the network force to
-use the same address for broadcast and ip machine and the network address doesn't
-exist.
-
-
-Someone could criticize this point of view, but if you use the standard
-ISO/OSI to configure Wireless network with you'll loss many ones configuring
-subnets; for each subnet usually you discard 2 IP number (Network and broadcast)
-and you cannot achieve the flexibility on IP assigning (geographically kind).
-You can find more on Appendix A about this.
-
-
-You could notice that step 2 is not present in Wired cards cause there's
-no particular settings to do there.
-
-!!5.2 Low Level Kernel Config
-
-
-
-Always it's a problem for Pc administration: to let kernel (or in general)
-see your hardware.
-
-
-Wireless cards are more complex because many of them usually have a Pcmcia
-plug, so first of all you have to let your kernel see Pcmcia adapter card,
-then you can try to install specific hardware driver for your Wireless card.
-
-
-
-
-
-
-
-So, in Pcmcia config you have to:
-
-
-
-
-
-
-***#install linux kernel source, from
-http://www.kernel.org to /usr/src/linux (see tar and gzip
-utilities)
-***#
-
-***#install linux pcmcia source, from
-ftp://projects.sourceforge.net/pub/pcmcia-cs to install to /usr/src/pcmcia (see tar
-and gzip utilities)
-***#
-
-***#config and recompile your kernel: read file README in your linux directory
-(/usr/src/linux)
-***#
-
-***#config and recompile your pcmcia source: under /usr/src/pcmcia use configure
-and make. Be sure your driver is here, else your have to install it following
-driver instructions (usually a tar zxvf driver.tgz under pcmcia dir is sufficient).
-After type "make all" to compile. At the end type "make install".
-
-***#
-
-***#After typed install you'll find some useful config files under /etc/pcmcia
-.
-***#
-
-
-
-
-
-In non pcmcia case:
-
-
-
-
-
-
-***#If your driver is present (99% not) under linux sources, you have
-to install it in a directory, then to compile it.
-***#
-
-
-
-Once you know module name you have to load it: in pcmcia config you only
-need to start pcmcia daemon (/etc/rc.d/init.d/pcmcia start for !RedHat), for
-other "modprobe module_name options". With options you'll give ioport,
-irq and data-link settings (see Par 5.3) to Wireless driver. Anyway your useful
-tools to know if hardware has correctly been seen by driver are:
-
-
-
-
-
-***#"tail /var/log/messages" that explains info about syslog
-***#
-
-***#"dmesg" for more info.
-***#
-
-***#/proc dir: ioports, devices, irq files and driver specific sub-directories.
-***#
-
-
-!!5.3 Data-link level setting
-
-
-
-
-
-What is that?
-
-
-
-Wired networks need only to connect each other and then you'll be able
-to set TCP/IP parameters.
-
-
-In opposite Wireless networks need data-link settings, such as:
-
-
-
-
-
-***#What kind of Wireless network I belong to? (Adhoc or Infrastructure)
-***#
-
-***#What channel I have to use?
-***#
-
-***#What subnet (BSSID) I belong to, what is my ESS ID?
-***#
-
-***#Is my communication protected by such a encryption algorithm? Length key?
-
-***#
-
-
-
-As you see there are many settings you have to adjust, the reason come
-from the architecture of Wireless network: there could be someone, in near
-distance, that could see your packets, use your services only pointing his
-antenna on the right direction and setting up right TCP/IP parameters.
-
-
-In addition there could be many Wireless subnets that could generate interference
-each other.
-
-
-So here are:
-
-
-
-
-
-***#Options at load-time module: "modprobe ray_cs essid='LINUX'"
-for example or
-***#
-
-***#Utilities at run-time driver: "rl2cfg eth1 master".
-***#
-
-
-!!5.4 Ip setting
-
-
-
-This is the third problem you have to face. Here situation become problematic
-only when your network begin to evolve in a bigger one.
-
-
-
-
-Remember Wireless IP Networking doesn't stress you if you don't stress it!
-
-
-!A simple configuration
-
-
-
-
-All the hosts view each other
-A - - - - - C
-\ /
-| \ / |
-/\
-| / \ |
-/ \
-B - - - - - D
-
-
-
-A configuration like this is very simple and don't require nothing special
-(at Ip level): you only need to assign an IP address for each host and to assign
-a coherent global netmask.
-
-!A more complex configuration
-
-
-
-
-A doesn't see B directly
-A <- - - -
-NO\ |
-TALK\ C
-\ |
-B <- - - -
-
-
-
-Here A and B can communicate only passing through C.
-
-
-If the network is in Infrastructure mode and C is the Access Point all
-is ok. In Adhoc mode you also can design a host to "master" capability
-(I know the term is not so formal!), a host that creates a BSS and to which
-any other host can join that BSS.
-
-
-Full connectivity now is reached at IP level: A and B talk to C using the
-same C interface, so if you try to ping from A to B you'll receive many ICMP
-REDIRECT packets from C, cause C is telling A that the destination is already
-in the network from which come the request.
-
-
-Solution: type a "echo 0 > /proc/sys/net/ipv4/conf/ethx/send_redirects"
-(where ethx is the interface on C towards A and C) to null all that.
-
-
-Another problem: what netmask I assign to A and C? If you assign a netmask
-to A that include A and C nothing works because A don't use the gateway (C)
-but make the ARP request with unknown destination MAC address.
-
-
-You could think to use proxy arp, but without effect cause proxy arp reply
-to source only when the destination is in a different interface from the source:
-this is not the case!!
-
-
-So you have to set a very little netmask (Win9x let it be 255.255.255.254,
-WinNT at least 255.255.255.248), and you have to assure that hosts A and C
-don't have the same net address.
-
-
-
-
-Examples:
-
-
-
-
-
-
-***#IP(A) = x.y.z.2/31, IP(B) = x.y.z.3/31. This doesn't work cause A asks
-for B in its network (ARP request) and C doesn't answer cause, for it, A and
-B belong to the same interface (so, no proxy arp).
-***#
-
-***#IP(A) = x.y.z.1/31, IP(B)= x.y.z.2/31. This works cause A ask to C (send
-requests to B with C MAC address) for B.
-***#
-
-
-
-In general with a netmask 255.255.255.254 system works with 2 IP changing
-only for the final bit.
-
-
-All that is a TCP/IP forcing but is the only method to obtain an high level
-of flexibility.
-
-
-Note: If you use an Access Point (network in Infrastructure mode) you haven't
-redirect problem, cause all is solved at data-link level (almost every Access
-Point acts as a bridge...). But Access Point are expansive (about 1000 USD
-or more) and it is more economic to use a P133 32MB Ram to forward, even with
-2 or more cards.
-
-!Internet Access
-
-
-
-
-A - - - - - C - - Internet
-\ /
-| \ / |
-/\
-| / \ |
-/ \
-B - - - - - D
-
-
-
-There is a number of situation:
-
-
-
-
-
-***#C is the only Public IP address. You only have to set private IP address
-(192.168.x.y for example) for the Wireless network enabling, on C, forwarding
-and masquering. A, B and D will have C as default GW.
-***#
-
-***#You have a public netmask visible from Internet and C is your default GW
-to Internet for the network. You only need to enable forwarding on C, setting
-up default GW on A, B and D to point to C.
-***#
-
-***#You have a public netmask visible from Internet and C is not the default
-GW to Internet. You have 2 possible solutions: Modify your default GW to let
-it point to C for your network. Symmetrically you have to let C point to default
-GW to go to Internet. You could, instead, enable proxy arp feature to C (echo
-1 > /proc/sys/net/ipv4/conf/ethx/proxy_arp where ethx is the interface towards
-the default GW) and set your default GW on C to point to the default GW. Proxy
-arp is a TCP/IP forcing but works well.
-***#
-
-
-!Mixed network: Wired and Wireless
-
-
-
-
-Internet
-\
-\ E
-\ /
-\ / Wireless
-A - - - - - C - - F
-\ / \
-| \ / | \
-Wired /\ G
-| / \ |
-/ \
-B - - - - - D
-
-
-
-Now C joins 2 networks: on the right Wireless and Wired on the left.
-
-
-More you have Internet Access, so in total you have 3 network cards in
-C.
-
-
-What IP Address I assign to hosts? You have 2 possible solutions:
-
-
-
-
-
-***#Split up network in 2 subnets: for example 192.168.1./24 and 192.168.2./24.
-This solution is quickly but is not scalable if you are using Internet IP addresses
-cause you have to drop too many IPs.
-***#
-
-***#Enable Proxy Arp feature to C for all 2 interfaces. Network parameters
-(net address and netmask) are the same for Wireless and Wired, but with proxy-arp
-enabled I can choose which IPs are on Wired and which on Wireless.
-***#
-
-
-
-
-
-Now we examine solution 2
-
-
-
-For example: Consider you have Internet public subnet x.y.z./24.
-
-
-
-
-Interfaces are:
-
-
-
-
-
-
-***#ifconfig eth0 x.y.z.C netmask 255.255.255.255 (Wired)
-***#
-
-***#ifconfig eth1 x.y.z.C netmask 255.255.255.255 (Wireless)
-***#
-
-***#ifconfig eth2 x.y.z.C netmask 255.255.255.255 (to Internet)
-***#
-
-
-
-
-
-Static routes on eth2:
-
-
-
-
-
-
-***#route add IPGW dev eth2
-***#
-
-***#route add default gw IPGW
-***#
-
-
-
-This route stands for addressing all Internet requests to your Default
-GW: as you notice, first you have to tell Linux where is the router, then let
-default requesting through it.
-
-
-
-
-Static routes on eth0:
-
-
-
-
-
-
-***#route add x.y.z.A dev eth0
-***#
-
-***#route add x.y.z.B dev eth0
-***#
-
-***#route add x.y.z.D dev eth0
-***#
-
-
-
-Hosts A,B and D on the Wired Network
-
-
-
-
-Static routes on eth1:
-
-
-
-
-
-
-***#route add x.y.z.E dev eth1
-***#
-
-***#route add x.y.z.F dev eth1
-***#
-
-***#route add x.y.z.G dev eth1
-***#
-
-
-
-Hosts E,F and G on the Wireless Network
-
-
-Note that flexibility is very high, but you have to manual set each host.
-
-
-
-----
-
-!!6. Setup
-
-
-Here I report some examples (I hope useful!) on how to configure more diffuse
-and not expansive Wireless Cards.
-
-!!6.1 General setup info
-
-
-
-Wireless cards have interface similar to any Ethernet cards, so you have
-to add in /etc/conf.modules:
-
-
-
-
-
-***#"alias ethx module", where ethx is the interface you want to
-assign to your wireless card and module is name of kernel module.
-***#
-
-***#"options module io=0xAAA irq=I ...", where 0xAAA is the io base
-address to assign the card, I is the IRQ and so on if there are other parameters.
-
-***#
-
-
-
-After this you'll be able to use ifconfig and route commands to configure
-your card at IP level.
-
-!!6.2 Proxim Symphony
-
-
-
-Network type: FHSS, Adhoc only and with proprietary protocol !OpenAir.
-
-
-Web site:
-http://www.proxim.com where you need to download documentation and driver for Linux
-and Win9x.
-
-
-Drivers come with source code to compile:
-
-
-
-
-
-***#untar it in a empty directory
-***#
-
-***#type make for help.
-***#
-
-***#make modules; make modules_install to install the driver rlmod.o and the
-utility rl2cfg.
-***#
-
-***#to run the driver (after modified /etc/conf.modules: see Par.6.1.) you
-only need to turn up the interface with ifconfig command.
-***#
-
-
-
-Utility rl2cfg (for help type man rl2cfg once done c step) let you change
-typical data-link level settings:
-
-
-
-
-
-***#"rl2cfg dev ethx sta" to set it to station (Slave)
-***#
-
-***#"rl2cfg dev ethx msta" to set it to master station (Master)
-***#
-
-***#"rl2cfg dev ethx alt" to set it to automatically mode
-***#
-
-
-
-This is all you have to know to get it properly working.
-
-!!6.3 Webgear Aviator 2.4 and !AviatorPro
-
-
-
-Network type: FHSS, Adhoc only for Aviator 2.4 and Infrastructure for !AviatorPro.
-
-
-These cards need more for working, because you have to compile Pcmcia source
-as they come with Pcmcia plug.
-
-
-Web site is
-http://www.webgear.com.
-
-
-To configure:
-
-
-
-
-
-***#You have to download source pcmcia and to expand it to /usr/src/pcmcia
-(see Par 5.2)
-***#
-
-***#Download driver form
-http://www.webgear.com and type "tar zxvf driver.tgz" in /usr/src/pcmcia
-directory.
-***#
-
-***#reconfig pcmcia (see Par 5.2)
-***#
-
-***#Following instructions you have to append to file /etc/pcmcia/config.opts
-entry "source ./ray_cs.opts".
-***#
-
-***#Note that in /etc/pcmcia/ray_cs.opts there is a line like this: "module
-"ray_cs" opts "...". Here you have to modify some settings
-at data-link level present in "opts" .
-***#
-
-
-
-
-
-Arguments:
-
-
-
-
-
-
-****pc_debug=x , where x is the log level.
-****
-
-****net_type=x, x=0 for !AdHoc, x=1 for Infrastructure.
-****
-
-****essid=x, x is the ESSID
-****
-
-
-
-Finally, to verify configuration with pc_debug > , you will see data-link
-messages in your console like these: "network started" for a new
-Wireless network created and "network joined" for a new Wireless
-network joined to another one.
-
-
-Also File /proc/ray_cs can help you: flied BSSID report to which Subnet
-you belong to, if it is null you can receive data from no one cards.
-
-!!6.4 Lucent Wavelan I, II, Orinoco products and Cabletron
-
-
-
-Network type: DSSS, Adhoc and Infrastructure.
-
-
-Lucent products are very professional ones.
-
-
-Web site:
-http://www.lucent.com and
-http://www.orinoco.net.
-
-
-Setup is like !WebGear-like: step 1,2,3 are similar
-
-
-Then you have to add to file /etc/pcmcia/config.opts: module "wavelan_cs"
-opts " ..." for Lucent Wavelan I module and "wavelan2_cs"
-opts " ...", for Lucent Wavelan II or Orinoco.
-
-
-Under opts you will specify:
-
-
-
-
-
-***#port_type=x, where x indicates Adhoc(3) or Infrastructure(1)
-***#
-
-***#channel=x, x=channel, option relevant for !AdHoc mode only.
-***#
-
-***#transmit_rate=x, to fix the speed rate: attention to this setting for compatibility
-with Cabletron cards.
-***#
-
-
-
-Note: Ideally, it is possible in a Linux Box to have 2 Lucent Wavelanx
-cards, one in Adhoc mode and the other in Infrastructure mode. Only one of
-them could properly works because, when starting pcmcia service, all 2 cards
-are set with same opts value (so in Adhoc or Infrastructure mode). So we have
-to create a Linux module (or maybe a user mode program) that can change data_link
-parameters at run-time such as access mode and channel used in Adhoc mode!
-
-
-
-
-
-The channel parameter is usually used to avoid interference with near other
-Wireless TX/RX.
-
-
-Lucent drivers could also be used for Cabletron cards
-http://www.cabletron.com
-!!6.5 YDI
-
-
-
-Network type: DSSS, Adhoc and Infrastructure.
-
-
-YDI sells very professional cards with antennas, amplifiers and more.
-
-
-Web-site
-http://www.ydi.com
-
-
-
-
-To install:
-
-
-
-
-
-
-***#untar it in a empty directory.
-***#
-
-***#type make for compile.
-***#
-
-***#make install to install the driver am930_isa and the wlanctl utility
-***#
-
-
-
-Once done you can choose if type manual commands using "wlanctl" data-link
-utility or run the "scripts/wlan" file or "scripts/rc.wlan" file to automatically
-config your network.
-
-
-In manual case these are major settings:
-
-
-
-
-
-***#"wlanctl scan ..." to search for BSSs already present.
-***#
-
-***#"wlanctl netlist" show you what's found with "wlanctl scan
-...".
-***#
-
-***#"wlanctl bsscreate ... ssid" to create a new network with ssid
-parameter.
-***#
-
-***#"wlanctl bssjoin bssid" to join the network identified by bssid.
-
-***#
-
-***#"wlanctl authen" and "wlanctl assoc" for authentication
-services.
-***#
-
-----
-
-!!7. More about Wireless
-
-!!7.1 A Wireless Linux distribution
-
-
-
-The wireless distribution !FlyingLinux started in October 1999 in the Telecommunication
-Systems Lab at Teleinformatics KTH with the objective of studying the possibilty
-of using MobileIPv4 and standard DHCP-based wireless access for student labs.
-
-
-
-
-
-The result of that work was the !FlyingLinux environment available for one
-hundred students and teachers during the 2G1303 project course that was held
-from March to May year 2000.
-
-
-!FlyingLinux is the first linux distribution oriented to mobility services.
-We have taken care of the security issues including Kerberos support and OpenSSH.
-
-
-
-
-
-!FlyingLinux is part of the Open Source movement. We have included software
-that have been developed at KTH under the GPL licence.
-
-
-You can find the Wireless Linux distribution at this
-Web Site.
-
-
-Mantainer: Alberto Escudero
-Email,
-----
-
-!!8. Useful links
-
-!!8.1 Open software link
-
-
-
-
-
-
-****
-Linux-wlan project
-****
-
-****
-Jean Tourrilhes Wireless Howto
-****
-
-
-!!8.2 Commercial link
-
-
-
-
-
-
-****
-Fatamorgana Computers
-****
-
-****
-Lucent web site
-****
-
-****
-YDI web site
-****
-
-****
-Siemens web site
-****
-
-----
-
-!!9. FAQ - Frequently asked questions
-
-
-Q1: What's the difference between BSSID and ESSID and when I need a ESSID?
-
-
-
-
-
-A1: BSSID is 48 bit number used to identify the BSS short area, where all
-hosts talk each other (eventually with an Access Point) ESSID is a variable
-length string that can let communicate different BSS are to extend it to a
-Extended Service Set (ESS). There is one Access Point for each BSS and all
-they talk together only if you belong to the same ESSID. Really you need ESSID
-if you have a large network with at least 2 Access Points.
-
-
-Q2: What Access Point I have to buy?
-
-
-A2: The less expansive you find: what is important is that the Access Point
-and the cards you are using use the same Physical Layer Specific: all FHSS
-compatible or all DSSS compatible. Attention to Proxim RangeLan2 cards that
-cannot talk with other standard FHSS because they use the proprietary protocol
-!OpenAir.
-
-
-Q3: What do I use the channel setting for?
-
-
-A3: When you have more network with different BSS (and with different vendors)
-you could have interference problem: changing channel on Access Points or in
-Adhoc mode hosts could help you avoiding this kind of problems.
-
-
-Q4: Why I cannot set channel on Infrastructure hosts?
-
-
-A4: Because the channel is decided by the Access Point.
-----
-
-!!10. Appendix A - Netmask 255.255.255.255, proxy arp and bridging
-
-
-Here we view some Linux advantages in Wireless Internetworking.
-
-
-Linux let you specify a netmask like 255.255.255.255 for an interface which
-can help you assign IP addresses in to any interface you want, for example
-one in eth0, another in eth1 and so on...
-
-
-This has not particularly side-effects.
-
-
-In addition you have proxy arp setting under /proc/sys/net/ipv4/conf/ethx/proxy_arp
-where ethx if your interface.
-
-
-If you "echo 1 > proxy_arp" you enable proxy_arp for that
-interface while with "echo 0 > proxy_arp" you disable it.
-
-
-What's proxy_arp? Quickly proxy arp help you when you want a router answer
-to an ARP request if the destination address is in another interface of the
-linux router.
-
-
-Example:
-
-
-
-
-192.168.1.1 ---- 192.168.1.2 Linux router 192.168.2.2 ----192.168.2.1
-
-
-
-To get this example working you should:
-
-
-
-
-Without proxy-arp
-
-
-
-
-
-
-***#In 192.168.1.1 host to set 192.168.1.2 as gateway
-***#
-
-***#In 192.168.2.1 host to set 192.168.2.2 as gateway
-***#
-
-***#pinging with success from any edge.
-***#
-
-
-
-
-
-With proxy-arp
-
-
-
-
-
-
-***#In 192.168.1.1 host to set 192.168.1.2 as gateway
-***#
-
-***#do not set gateway for 192.168.2.1 host but enable proxy_arp for right
-interface of the router.
-***#
-
-***#pinging with success from any edge
-***#
-
-
-
-Proxy-arp in 2. case let the linux router answer when you ping from 192.168.2.1
-host, saying that it has the 192.168.1.1 host so it can answer for it. After,
-when the source start sending ICMP packet, Linux router knows that it have
-to redirect it to the real host 192.168.1.1
-
-
-In Wireless network proxy arp can help you if you have many Linux boxes
-that acts as IP Forwarders and you wouldn't set to all hosts a number of static
-route.
-
-
-You also can experiment Linux bridging in Wireless network:
-
-
-
-
-
-***#install a recent stable kernel
-***#
-
-***#download good bridge utils at
-http link or
-ftp link
-***#
-
-
-
-Bridging should be more simple to manage.
-----
-
-!!11. Appendix B - Siemens DECT Radio Modem
-
-
-Web Site:
-http://www.siemens.com
-
-What's that? These 2 components are not real PC cards but are more like
-modems that you use as external device.
-
-
-
-
-Host1-serial - RadioModem1 - - - - - RadioModem2 - serial-Host2
-
-
-
-How can I connect it?
-
-
-If you see them in an abstract vision you can model them like this:
-
-
-
-
-Host1-serial - - NULL MODEM CABLE - - serial-Host2
-
-
-
-So you'd have a connection between 2 far serials with 2 possible configurations:
-
-
-
-
-
-
-
-
-***#Linux with Windows, Linux has a daemon that answer to a ppp call while
-Windows has a Dial up connection under Remote Access.
-***#
-
-***#Linux with Linux, where you can run (on all 2 hosts) a ppp connection,
-with IP addresses inverted.
-***#
-
-
-
-For 1 you can use this simple script in Linux:
-
-
-"/usr/sbin/pppd -detach lock idle 300 crtscts connect "/usr/sbin/chat
--v TIMEOUT 5 AT OK AT OK AT OK AT OK" IPLINUX:IPWINDOWS /dev/ttySx 115200
-disconnect "/usr/sbin/chat -v AT OK" ms-dns IPDNS"
-
-
-where:
-
-
-
-
-
-****/dev/ttySx is your serial port,
-****
-
-****IPDNS is the IP address of your dns server,
-****
-
-****IPLINUX is the Linux IP address as IPWINDOWS is the Windows IP address.
-
-****
-
-
-
-The above script is need for letting Windows believe there is a modem on
-the serial end!
-
-
-In Windows you need to create a Dial Up connection with crtscts enabled,
-speed at 115200 and with a stupid number to call (need by Remote Access but
-absolutely not used).
-
-
-With 2 Linux boxes you only have to run a very simple script like this
-at each Linux side:
-
-
-"/usr/sbin/pppd passive local crtscts IPLINUX1:IPLINUX2 /dev/ttySx
-115200 noauth persist"
-
-
-where you'll invert IPLINUX1 with IPLINUX2 at the other edge.
-
-
-Note that you can do authentication even Linux-Windows than in Linux-Linux
-if you want
.
-----
+Describe [HowToWirelessHOWTO]
here.
