From ec32d9d91d5fd9fe4d3bd4d602efe2fae63c5fdb Mon Sep 17 00:00:00 2001 From: binh <> Date: Mon, 17 Jan 2005 12:43:40 +0000 Subject: [PATCH] Removed extraneous information. Binh. --- .../Linux-Networking/Bandwidth-Limiting.xml | 12 +- LDP/guide/docbook/Linux-Networking/DHCP.xml | 680 ------------------ .../docbook/Linux-Networking/Media-Types.xml | 209 ++---- .../docbook/Linux-Networking/WaveLAN.xml | 2 +- 4 files changed, 58 insertions(+), 845 deletions(-) diff --git a/LDP/guide/docbook/Linux-Networking/Bandwidth-Limiting.xml b/LDP/guide/docbook/Linux-Networking/Bandwidth-Limiting.xml index 4fa0206c..f8f0d8e8 100644 --- a/LDP/guide/docbook/Linux-Networking/Bandwidth-Limiting.xml +++ b/LDP/guide/docbook/Linux-Networking/Bandwidth-Limiting.xml @@ -21,17 +21,12 @@ Let's imagine the following situation:   * We have 115,2 kbits/s ppp (modem) internet link (115,2/10 = 11,5 kbytes/ s). Note: with eth connections (network card) we would divide 115,2 by 8; with ppp we divide by 10, because of start/stop bits (8 + 1 + 1 = 10). -   * We have some LAN stations and their users are doing bulk downloads all the time. -   * We want web pages to open fast, no matter how many dowloads are happening. -   * Our internet interface is ppp0. -   * Our LAN interface is eth0. -   * Our network is 192.168.1.0/24 @@ -341,17 +336,24 @@ explain below. ----------------------------------------------------------------------------- 3.3. Solving remaining problems + OK, we have installed Squid and configured it to use delay pools. I bet nobody wants to be restricted, especially our clever LAN users. They will likely try to avoid our limitations, just to download their favourite mp3s a little faster (and thus causing your headache). + + I assume that you use IP-masquerade on your LAN so that your users could use IRC, ICQ, e-mail, etc. That's OK, but we must make sure that our LAN users will use our delay pooled Squid to access web pages and use ftp. + + We can solve most of these problems by using ipchains (Linux 2.2.x kernels) or iptables (Linux 2.4.x kernels). + + ----------------------------------------------------------------------------- 3.3.1. Linux 2.2.x kernels (ipchains) diff --git a/LDP/guide/docbook/Linux-Networking/DHCP.xml b/LDP/guide/docbook/Linux-Networking/DHCP.xml index 031a2b77..8807d0c7 100644 --- a/LDP/guide/docbook/Linux-Networking/DHCP.xml +++ b/LDP/guide/docbook/Linux-Networking/DHCP.xml @@ -30,686 +30,6 @@ especially in large networks or networks which have lots of mobile users. Resources section at the end of the document). You can also read [32]http://web.syr.edu/~jmwobus/comfaqs/dhcp.faq.html. - This mini-HOWTO covers both the DHCP _SERVER_ daemon as well as DHCP - _CLIENT_ daemon. Most people need the client daemon which is used by - workstations to obtain network information from a remote server. The - server daemon is used by system administrators to distribute network - information to clients so if you are just a regular user you need the - _CLIENT_ daemon. - _________________________________________________________________ - -3. Client Setup - - Currently there are three different DHCP client programs for Linux, - dhcpcd, pump and dhclient. This mini-HOWTO deals primarily with - dhcpcd. - _________________________________________________________________ - -3.1. Downloading the client daemon (dhcpcd) - - Depending on your distribution you might have to download the DHCP - client daemon. If you want to compile it from the source you package - you need is called dhcpcd and the current version is 1.3.18. It is - maintained by Sergei Viznyuk <[33]sergei@phystech.com> and today it - comes as a binary package with most distributions. - - dhcpcd source can be downloaded from following locations - - * [34]ftp://ftp.phystech.com/pub/ (Primary site) - * [35]http://www.cps.msu.edu/~dunham/out/ - - Then follow the instructions below. They should be the same. - _________________________________________________________________ - -3.2. Slackware - - You can download the latest copy of the DHCPcd from any Metalab mirror - or following: - - * [36]ftp://metalab.unc.edu/pub/Linux/system/network/daemons - * [37]ftp://ftp.phystech.com/pub/ (Primary site) - - Download the latest version of dhcpcd.tar.gz. - - * Unpack it - tar -zxvf dhcpcd-1.3.18pl1.tar.gz - * cd into the directory and make dhcpcd - cd dhcpcd-1.3.18pl1 - make - * Install it (you have to run the following command as root) - make install - - This will create the directory /etc/dhcpc where DHCPcd will store the - DHCP information and dhcpcd file will be copied into /usr/sbin. - - In order to make the system initialize using DHCP during boot type: - - cd /etc/rc.d - - mv rc.inet1 rc.inet1.OLD - - This will move the old network initialization script into - rc.inet1.OLD. You now need to create the new rc.inet1 script. - Following code is all you need: - -#!/bin/sh -# -# rc.inet1 This shell script boots up the base INET system. - -HOSTNAME=`cat /etc/HOSTNAME` #This is probably not necessary but I - #will leave it in anyways - -# Attach the loopback device. -/sbin/ifconfig lo 127.0.0.1 -/sbin/route add -net 127.0.0.0 netmask 255.0.0.0 lo - -# IF YOU HAVE AN ETHERNET CONNECTION, use these lines below to configure the -# eth0 interface. If you're only using loopback or SLIP, don't include the -# rest of the lines in this file. - -/usr/sbin/dhcpcd - - Save it and reboot your computer. - - When you are finished go the [38]last step. - _________________________________________________________________ - -3.3. RedHat 6.x and Mandrake 6.x - - DHCPcd configuration under RedHat 6.0+ is really easy. All you need to - do is start the Control Panel by typing control-panel. - - * Select "Network Configuration" - * Click on Interfaces - * Click Add - * Select Ethernet - * In the Edit Ethernet/Bus Interface select "Activate interface at - boot time" as well as select "DHCP" as "Interface configuration - protocol" - - Please note that in RedHat 6.x Redhat as default includes a DHCP - client called pump instead of above mentioned dhcpcd. CD-ROM does - include dhcpcd RPM so if you have no luck with pump try with dhcpcd. - After you install dhcpcd (e.g. rpm -i dhcpcd-1.3.17pl2-1.i386.rpm) you - will have to make some [39]changes. - - Additional notes from Alexander Stevenson - <[40]alexander.stevenson@home.com>: - - I had no luck with DHCPcd. What finally worked for me was "pump", - which comes with Linux Mandrake 6.0 (and so I assume it is included - with RedHat as well). The command I used was: - - pump -i eth0 -h hostname - - It didn't matter what "hostname" was, but without it the server would - not respond. - - I then changed the line in my /sbin/ifup script to reflect the change; - the default version does not have the -h switch, and so didn't work - for me. - - Basically, if you're using linuxconf, and after setting the adapter to - "DHCP" it still doesn't work, try adding a "-h hostname" to the pump - line in the /sbin/ifup script. My script now looks like this: -... -if [ -n "$PUMP" ]; then - echo -n "Determining IP information for $DEVICE..." - if /sbin/pump -i $DEVICE -h hostname; then - echo " done." - else - echo " failed." - exit 1 - fi -else ... - - Another more elegant way to add hostname field is provided by Aad van - der Klaauw: - - Currently i'm configuring a gateway system at home, needed to set the - MAC address and use the '-h hostname' workaround. So I decided to - *not* change the script but to use the configure file. In my - /etc/sysconfig/network-scripts/ifcfg-eth0 I have added the following -DEVICE="eth0" -MACADDR="00:11:22:33:44:55" -DHCP_HOSTNAME="trigger_for_terayon" - - Which will survive upgrades, and is imho a "cleaner" way. - - That is it. Reboot your machine or type /sbin/ifup eth0 on the command - line. - _________________________________________________________________ - -3.4. RedHat 5.x - - DHCPcd configuration under RedHat 5.0+ is really easy. All you need to - do is start the Control Panel by typing control-panel. - - * Select "Network Configuration" - * Click on Interfaces - * Click Add - * Select Ethernet - * In the Edit Ethernet/Bus Interface select "Activate interface at - boot time" as well as select "DHCP" as "Interface configuration - protocol" - - When you are finished go the [41]last step. - _________________________________________________________________ - -3.5. RedHat 4.x and Caldera OpenLinux 1.1/1.2 - - DHCPcd is included in the standard RedHat distribution as an RPM and - you can find it on your distribution's CD-ROM in RPMS directory or you - can download it from: - - [42]ftp://ftp.redhat.com/pub/redhat/redhat-4.2/i386/RedHat/RPMS/dhcpcd - -0.6-2.i386.rpm - - Install it with rpm -i dhcpcd-0.6-2.i386.rpm. - - Alternatively you can compile your own version by following the steps - outlined in the [43]Slackware. - - The following information was provided to me by nothing - <[44]nothing@cc.gatech.edu>. - - Removed my static ip and name from /etc/resolv.conf. However, I did - leave in the search line and my two nameserver lines (for some - reason my dhcpcd never creates a /etc/dhcpc/resolv.conf, so I have - to use a static /etc/resolv.conf). - - In /etc/sysconfig/network I removed the HOSTNAME and GATEWAY - entries. I left the other entries as is (NETWORKING, DOMAINNAME, - GATEWAYDEV). - - In /etc/sysconfig/network-scripts/ifcfg-eth0 I removed the IPADDR, - NETMASK, NETWORK, and BROADCAST entries. I left DEVICE and ONBOOT - as is. I changed the BOOTPROTO line to BOOTPROTO=dhcp. - - Save the file. Reboot your computer. - - When you are finished go the [45]last step. - _________________________________________________________________ - -3.6. Debian - - There is a deb package of DHCPcd (make sure it starts with dhcpcd) at: - - [46]http://ftp.debian.org/debian/dists/slink/main/binary-i386/net/ - - Or, follow the [47]Slackware installation instructions. - - To unpack the deb package type dpkg -i - /where/ever/your/debian/packages/are/dhcpcd*deb. - - It appears that there isn't a need for any DHCPcd configuration - because: - - - The dhcpcd package installs it's startup script as usual for debian - packages in /etc/init.d/package_name, here as /etc/init.d/dhcpcd, and - links this to the various /etc/rc?.d/ directories. - - --From: Heiko Schlittermann <[48]heiko@os.inf.tu-dresden.de> - - The contents of the /etc/rc?.d/ dirs is then executed at boot time. - - If you don't reboot after installing you should consider starting the - daemon manually: /etc/init.d/dhcpcd start. - - When you are finished go the [49]last step. - _________________________________________________________________ - -3.7. LinuxPPC and MkLinux - - Following section has been written by R. Shapiro - - As of the "1999" (R5) release, Linuxppc is now almost completely - compatible with Redhat 6, with one caveat (see below). In general the - instructions are exactly the same as for the current release of - [50]RedHat 6.x and Mandrake 6.x. - - The remaining problem is that Redhat 6 uses the 'pump' client for dhcp - by default, and 'pump' doesn't work reliably in Linuxppc. To get - around this, you should install the latest dhcpcd from Sergei Viznyuk, - and then edit /sbin/ifup to use dhcpcd instead of pump. - - Change -if [ "$BOOTPROTO" = bootp -o "$BOOTPROTO" = dhcp ]; then - PUMP=true - fi - - if [ -n "$PUMP" ]; then - - with - if [ "$BOOTPROTO" = bootp ]; then - echo " done." - else - echo " failed." - exit 1 - fi - elif [ "$BOOTPROTO" = dhcp ]; then - echo -n "Determining IP information for $DEVICE..." - if /sbin/dhcpcd -d $DEVICE ; then - if [ -f /etc/dhcpc/dhcpcd-${DEVICE}.exe ]; then - /etc/dhcpc/dhcpcd-${DEVICE}.exe - fi - - and a coresponding changes for ifdown. Change -if [ "$BOOTPROTO" = bootp -o "$BOOTPROTO" = dhcp ]; then -.... -fi - - with -if [ "$BOOTPROTO" = bootp ]; then -fi - -if [ "$BOOTPROTO" = dhcp ]; then - if [ -f /var/run/dhcpcd-${DEVICE}.pid ]; then - kill `cat /var/run/dhcpcd-${DEVICE}.pid` - rm -f /var/run/dhcpcd-${DEVICE}.pid - fi -fi - - A working ppc rpm for dhcpcd is included on the Linuxppc 1999 cd; a - slightly later rpm is available in the contrib directory on - [51]ftp://ftp.linuxppc.org/. Sources, which compile out of the box in - Linuxppc 1999, are available from - [52]ftp://ftp.phystech.com/pub/dhcpcd-1.3.17-pl9.tar.gz. - _________________________________________________________________ - -3.8. Tying it all together - - After your machine reboots your network interface should be - configured. Type: ifconfig. - - You should get something like this: - lo Link encap:Local Loopback - inet addr:127.0.0.1 Bcast:127.255.255.255 Mask:255.0.0.0 - UP BROADCAST LOOPBACK RUNNING MTU:3584 Metric:1 - RX packets:302 errors:0 dropped:0 overruns:0 frame:0 - TX packets:302 errors:0 dropped:0 overruns:0 carrier:0 coll:0 - -eth0 Link encap:Ethernet HWaddr 00:20:AF:EE:05:45 - inet addr:24.128.53.102 Bcast:24.128.53.255 Mask:255.255.254.0 - ^^^^^^^^^^^^^^^^^^^^^^^ - UP BROADCAST NOTRAILERS RUNNING MULTICAST MTU:1500 Metric:1 - RX packets:24783 errors:1 dropped:1 overruns:0 frame:1 - TX packets:11598 errors:0 dropped:0 overruns:0 carrier:0 coll:96 - Interrupt:10 Base address:0x300 - - If you have some normal number under inet addr you are set. If you see - 0.0.0.0 don't despair, it is a temporary setting before dhcpcd - acquires the IP address. If even after few minutes you are seeing - 0.0.0.0 please check out [53]Troubleshooting. DHCPcd is a daemon and - will stay running as long as you have your machine on. Every three - hours it will contact the DHCP server and try to renew the IP address - lease. It will log all the messages in the syslog (on Slackware - /var/adm/syslog, RedHat/OpenLinux /var/log/syslog). - - One final thing. You need to specify your nameservers. There are two - ways to do it, you can either ask your provider to provide you with - the addresses of your name server and then put those in the - /etc/resolv.conf or DHCPcd will obtain the list from the DHCP server - and will build a resolv.conf in /etc/dhcpc. - - I decided to use DHCPcd's resolv.conf by doing the following: - - Back up your old /etc/resolv.conf: mv /etc/resolv.conf - /etc/resolv.conf.OLD - - If directory /etc/dhcpc doesn't exist create it: mkdir /etc/dhcpc - - Make a link from /etc/dhcpc/resolv.conf to /etc/resolv.conf: ln -s - /etc/dhcpc/resolv.conf /etc/resolv.conf - - If that doesn't work try this (fix suggested by - <[54]nothing@cc.gatech.edu> with a little amendment by Henrik - Stoerner): - - This last step I had to perform only because my dhcpcd doesn't create - an /etc/dhcpc/resolv.conf. In /etc/sysconfig/network-scripts/ifup I - made the following changes (which are a very poor hack, but they work - for me): -elif [ "$BOOTPROTO" = dhcp -a "$ISALIAS" = no ]; then - echo -n "Using DHCP for ${DEVICE}... " - /sbin/dhcpcd -c /etc/sysconfig/network-scripts/ifdhcpc-done ${DEVICE} - echo "echo \$$ > /var/run/dhcp-wait-${DEVICE}.pid; exec sleep 30" | sh - - if [ -f /var/run/dhcp-wait-${DEVICE}.pid ]; then - ^^^^ - echo "failed." - exit 1 - - I changed to: -elif [ "$BOOTPROTO" = dhcp -a "$ISALIAS" = no ]; then - echo -n "Using DHCP for ${DEVICE}... " - /sbin/dhcpcd - echo "echo \$$ > /var/run/dhcp-wait-${DEVICE}.pid; exec sleep 30" | sh - - if [ ! -f /var/run/dhcp-wait-${DEVICE}.pid ]; then - ^^^^^^ - echo "failed." - exit 1 - - Note: Notice the ! (bang) in if [ ! -f - /var/run/dhcp-wait-${DEVICE}.pid ]; - - Now sit back and enjoy :-). - _________________________________________________________________ - -3.9. Various notes - - Following step(s) are not necessary but might be useful to some - people: - - a. If you need network connectivity only occasionally you can start - dhcpcd from the command line (you have to be root to do this) - with: /usr/sbin/dhcpcd. - When you need to down (turn off) the network type /usr/sbin/dhcpcd - -k. - _________________________________________________________________ - -3.10. Troubleshooting - - If you have followed the steps outlined above and you are unable to - access the network there are several possible explanations: - _________________________________________________________________ - -3.10.1. Your network card is not configured properly - - During the boot up process your Linux will probe your network card and - should say something along these lines: -eth0: 3c509 at 0x300 tag 1, 10baseT port, address 00 20 af ee 11 11, IRQ 10. -3c509.c:1.07 6/15/95 becker@cesdis.gsfc.nasa.gov - - If a message like this doesn't appear your ethernet card might not be - recognized by your Linux system. If you have a generic ethernet card - (a NE2000 clone) you should have received a disk with DOS utilities - that you can use to set up the card. Try playing with IRQs until Linux - recognizes your card (IRQ 9,10,12 are usually good). - _________________________________________________________________ - -3.10.2. Your DHCP server supports RFC 1541/My DHCP server is Windows NT - - Try running dhcpcd by typing dhcpcd -r. - - Use ifconfig to check if your network interface is configured (wait - few seconds for the configuration process, initally it will say - Inet.addr=0.0.0.0) - - If this solves your problem add the "-r" flag to the boot up scripts, - ie: instead of /sbin/dhcpcd you will have /sbin/dhcpcd -r. - - For example under RedHat edit script - /etc/sysconfig/network-scripts/ifup and change the following: - IFNAME=$[ {DEVICE} \ - "/sbin/dhcpcd -r -c /etc/"- etc etc. - _________________________________________________________________ - -3.10.3. During bootup I get error message "Using DHCP for eth0 ... failed" -but my system works fine. - - You are most likely using RedHat and you haven't followed instructions - carefully :-). You are missing the ! (bang) in one of the if - statements. Jump [55]here and check how to fix it. - _________________________________________________________________ - -3.10.4. My network works for few minutes and then stops responding - - There are some reports of gated (gateway daemon) screwing up routing - on Linux boxes which results in problem described above. Check if - gated is running with: ps -auxww | grep gate. - - If it is try removing it with RedHat's RPM manager or removing the - entry in /etc/rc.d/. - _________________________________________________________________ - -3.10.5. My ethernet card is recognized during boot up but I still get "NO -DHCPOFFER" message in my logs. I also happen to have a PCMCIA ethernet card. - - You need to make sure that you have the 10BaseT port ("phone" plug) on - your network card activated. Best way to verify it is to check what - kind of connector your card is configured for during bootup e.g. -eth0: 3c509 at 0x300 tag 1, 10baseT port, address 00 20 af ee 11 11, IRQ 10. - ^^^^^^^^^^^^ -3c509.c:1.07 6/15/95 becker@cesdis.gsfc.nasa.gov - - I have received reports of laptop users having this kind of problems - due to the PCMCIA utilities (specifically ifport) that would set the - connector type to 10Base2 (thinnet). You have to make sure you use - 10BaseT for your connection. If you are not reconfigure the card and - restart the computer. - _________________________________________________________________ - -3.10.6. My DHCP client broadcasts requests but no one answers (Contributed -by Peter Amstutz) - - On some systems, you need to include some hostname for your machine as - part of the request. With dhcpcd, do this with dhcpcd -h foohost - Probably the hostname wanted will be your account username on the - network. - _________________________________________________________________ - -3.10.7. I have followed all the steps but still my machine is not able to -connect - - The cable modem will usually memorize the ethernet address of your - network card so if you connect a new computer or switch network cards - you will somehow have to "teach" your cable modem to recognize the new - computer/card. Usually you can turn of the modem and bring it back up - while computer is on or you will have to call tech support and tell - them that you have changed a network card in the computer. - - You have firewall rules (ipfwadm rules) that disallow port 67/68 - traffic used by DHCP to distribute configuration info. Check your - firewall rules carefully. - _________________________________________________________________ - -3.10.8. I have MediaOne Express service and I still can't connect. - - It appears that MediaOne has been using adding some things to DHCP - that shouldn't be there. Supposedly this is not a problem anymore but - if you experience outages check for these things. If you are (un)lucky - to have Windows NT on your machine if you go into Event Viewer you - will see a warning like this: -DHCP received an unknown option 067 of length 005. The raw option data is -given below. - -0000: 62 61 73 69 63 basic - - If this is the problem go to [56]ftp://vanbuer.ddns.org/pub/ and - either download a binary or get the source for the change. - _________________________________________________________________ - -3.11. Alternative DHCP client (ISC dhclient) - - If you have not had success getting your Linux connection running with - the dhcpcd you might want to try ISC dhclient. dhclient comes with the - DHCP distribution from ISC which includes both a DHCP client and a - DHCP server. Instructions on how to get and compile the DHCP - distribution can be found [57]here. When you are done with it please - return to this section to configure the client. - - Note: Following information has been provided by Ted Lemon - <[58]mellon@isc.org> one of the authors of dhclient. - - With the current version of the DHCP client, you don't actually need a - dhclient.conf. All you have to do is invoke dhclient e.g.: - /sbin/dhclient. - - This will configure all broadcast interfaces. If this doesn't work or - you want to specify only one interface create a /etc/dhclient.conf - file with this example configuration. -interface "eth0" { - send dhcp-client-identifier 1:xx:xx:xx:xx:xx:xx; - send dhcp-lease-time 86400; -} - - Here we assume that the ethernet interface is eth0. If not change - accordingly. Also replace xx:xx:xx:xx:xx with your ethernet address. - This dhclient.conf makes the client look more like a Win95 client. - _________________________________________________________________ - -4. DHCP Server Setup - -4.1. DHCP server for UNIX - - There are several DHCP servers available for U*X-like OSes, both - commercial and free. One of the more popular free DHCP servers is Paul - Vixie/ISC DHCPd. Currently the latest version is 2.0 (suggested for - most users) but 3.0 is in beta testing. You can get them from - - [59]ftp://ftp.isc.org/isc/dhcp/ - - Some of the distributions provide binary packages for dhcpd so skip - the following section if you got it installed that way. - - After you download unpack it. After you do cd into the distribution - directory and type: ./configure - - It will take some time to configure the settings. After it is done - type: make and make install. - _________________________________________________________________ - -4.2. DHCP server configuration - - When done with installation type ifconfig -a. You should see something - like this: -eth0 Link encap:10Mbps Ethernet HWaddr 00:C0:4F:D3:C4:62 - inet addr:183.217.19.43 Bcast:183.217.19.255 Mask:255.255.255.0 - UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 - RX packets:2875542 errors:0 dropped:0 overruns:0 - TX packets:218647 errors:0 dropped:0 overruns:0 - Interrupt:11 Base address:0x210 - - If it doesn't say MULTICAST you should reconfigure your kernel and add - multicast support. On most systems you will not need to do this. - - Next step is to add route for 255.255.255.255. Quoted from DHCPd - README: - - "In order for dhcpd to work correctly with picky DHCP clients - (e.g., Windows 95), it must be able to send packets with an IP - destination address of 255.255.255.255. Unfortunately, Linux - insists on changing 255.255.255.255 into the local subnet broadcast - address (here, that's 192.5.5.223). This results in a DHCP protocol - violation, and while many DHCP clients don't notice the problem, - some (e.g., all Microsoft DHCP clients) do. Clients that have this - problem will appear not to see DHCPOFFER messages from the server." - - Type: route add -host 255.255.255.255 dev eth0 - - If you get a message "255.255.255.255: Unknown host", you should try - adding the following entry to your /etc/hosts file: -255.255.255.255 all-ones - - Then, try: -route add -host all-ones dev eth0 - - or -route add 255.255.255.0 dev eth0 - - eth0 is of course the name of the network device you are using. If it - differs change appropriately. - _________________________________________________________________ - -4.3. Options for DHCPd - - Now you need to configure DHCPd. In order to do this you will have to - create or edit /etc/dhcpd.conf. There is a graphical interface for - dhcpd configuration under KDE ( [60]http://www.kde.org/ ) called - kcmdhcpd that is very similar to the DHCP configurator on Windows NT. - When KDE 2.0 comes out it should come with kcmdhcpd or you could get - it directly from: - - [61]ftp://ftp.us.kde.org/pub/kde/unstable/apps/network/ - - If you want to configure it by hand follow instructions below. - - Most commonly what you want to do is assign IP addresses randomly. - This can be done with settings as follows: -# Sample /etc/dhcpd.conf -# (add your comments here) -default-lease-time 600; -max-lease-time 7200; -option subnet-mask 255.255.255.0; -option broadcast-address 192.168.1.255; -option routers 192.168.1.254; -option domain-name-servers 192.168.1.1, 192.168.1.2; -option domain-name "mydomain.org"; - -subnet 192.168.1.0 netmask 255.255.255.0 { - range 192.168.1.10 192.168.1.100; - range 192.168.1.150 192.168.1.200; -} - - This will result in DHCP server giving a client an IP address from the - range 192.168.1.10-192.168.1.100 or 192.168.1.150-192.168.1.200. It - will lease an IP address for 600 seconds if the client doesn't ask for - specific time frame. Otherwise the maximum (allowed) lease will be - 7200 seconds. The server will also "advise" the client that it should - use 255.255.255.0 as its subnet mask, 192.168.1.255 as its broadcast - address, 192.168.1.254 as the router/gateway and 192.168.1.1 and - 192.168.1.2 as its DNS servers. - - If you need to specify a WINS server for your Windows clients you will - need to include the netbios-name-servers option e.g. -option netbios-name-servers 192.168.1.1; - - You can also assign specific IP addresses based on clients ethernet - address e.g. -host haagen { - hardware ethernet 08:00:2b:4c:59:23; - fixed-address 192.168.1.222; -} - - This will assign IP address 192.168.1.222 to a client with ethernet - address 08:00:2b:4c:59:23. - - You can also mix and match e.g. you can have certain clients getting - "static" IP addresses (e.g. servers) and others being alloted dynamic - IPs (e.g. mobile users with laptops). There are a number of other - options e.g. nis server addresses, time server addresses etc., if you - need any of those options please read the dhcpd.conf man page. - _________________________________________________________________ - -4.4. Starting the server - - There is only one thing to do before starting the server. In most - cases DHCP installation doesn't create a dhcpd.leases files. This file - is used by DHCPd to store information about current leases. It is in - the plain text form so you can view it during the operation of DHCPd. - To create dhcpd.leases type: -touch /var/state/dhcp/dhcpd.leases - - This will create an empty file (file size = 0). Some of the older - version of dhcpd 2.0 placed the file in /etc/dhcpd.leases. You do not - need to make any changes to the leases file it will be manipulated by - the dhcpd. If you get a message saying that file exists simply ignore - it and go to the next step. - - You can now invoke the DHCP server. Simply type (or include in the - bootup scripts) -/usr/sbin/dhcpd - - This will invoke dhcpd on eth0 device. If you want to invoke it on - another device simply supply it on the command line e.g. -/usr/sbin/dhcpd eth1 - - To verify that everything is working fine you should first turn on the - debugging mode and put the server in foreground. You can do this by - typing -/usr/sbin/dhcpd -d -f - - Then boot up one of your clients and check out the console of your - server. You will see a number of debugging messages come up. If - everything works out fine you are done :-). Quit dhcpd and start it - without the -d -f and arguments. If you want dhcpd to start at boot-up - include dhcpd in e.g. -/etc/rc.d/rc.local - _________________________________________________________________ - 4.5. Other interesting documents Linux Magazine has a pretty good article in their April issue called diff --git a/LDP/guide/docbook/Linux-Networking/Media-Types.xml b/LDP/guide/docbook/Linux-Networking/Media-Types.xml index a82c0371..51887703 100644 --- a/LDP/guide/docbook/Linux-Networking/Media-Types.xml +++ b/LDP/guide/docbook/Linux-Networking/Media-Types.xml @@ -6,65 +6,39 @@ Media Types -Common network media include twisted pair (UTP and STP), coaxial cable, fiber-optic cable, and wireless -transmissions via infrared and radio waves. Network media are usually chosen based on several criteria: -their cost, their vulnerability to EMI and eavesdropping, their bandwidth, and the maximum distance at -which they can be used. +Common network media include twisted pair (UTP and STP), coaxial cable, fiber-optic cable, and wireless transmissions via infrared and radio waves. Network media are usually chosen based on several criteria: their cost, their vulnerability to EMI and eavesdropping, their bandwidth, and the maximum distance at which they can be used. + +Twisted Pair Ethernet Cable Unshielded Twisted Pair (UTP) -UTP is the most common type of network cable in use today. UTP consits of one or more pairs of insulated -copper wires. The wires are twisted together to reduce crosstalk, and enclosed in a plastic insulator. -UTP is the type of cable used in telephone systems. +UTP is the most common type of network cable in use today. UTP consits of one or more pairs of insulated copper wires. The wires are twisted together to reduce crosstalk, and enclosed in a plastic insulator. UTP is the type of cable used in telephone systems. -UTP cables are generally wires using RJ-45 jacks and plugs. These are 8-conductor connectors similar to -the RJ-11 connectors used in telephone cables. UTP is inexpensive and easy to install compared with other -types of cable, although the differenet types of UTP vary in cost. +UTP cables are generally wires using RJ-45 jacks and plugs. These are 8-conductor connectors similar to the RJ-11 connectors used in telephone cables. UTP is inexpensive and easy to install compared with other types of cable, although the differenet types of UTP vary in cost. -Copper wire has a high level of attenuation. YTP cable is limited to transmission distances of 100 meters -or less. UTP is more susceptible to interference (EMI) than mos types of cable, and is vaulnerable to -eavesdropping since its own emissions are not shielded. +Copper wire has a high level of attenuation. YTP cable is limited to transmission distances of 100 meters or less. UTP is more susceptible to interference (EMI) than mos types of cable, and is vaulnerable to eavesdropping since its own emissions are not shielded. -Types of UTP cable are defined by the EIA standards, which specify the three categories of cable. Category -3 is the minimum requiredment for networking, and Category 5 is the highest-quality network cable. The UTP -categories and the bandwidth they support are summarized below. +Types of UTP cable are defined by the EIA standards, which specify the three categories of cable. Category 3 is the minimum requiredment for networking, and Category 5 is the highest-quality network cable. The UTP categories and the bandwidth they support are summarized below. Category Maximum Data and Transfer Rate Description -3 10 Mbps Least expensive network cable, commonly used -4 16 Mbps Medium quality; rarely used -5 100 Mbps Highest quality +3 10 Mbps Least expensive network cable, commonly used +4 16 Mbps Medium quality; rarely used +5 100 Mbps Highest quality > Start Binh -5 1000Mbps Highest Quality +5 1000Mbps Highest Quality > End Binh - Shielded Twisted Pair (STP) -STP cable is similar to UTP, but inclues a foil or wire mesh shield between the wire pairs and -the outer insulation. The shield is electrically grounded, and reduces emissions and -susceptibility to EMI. - -STP cable is used in some Token Ting and AppleTalk networks. STP is more expensive than -UTP, and its thickness and rigidity make it more difficult to install. It also uses grounded -connection connectors, adding to the expense. - -STP uses the same copper wires as UTP as the same level of attenuation, and therefore the same -maximum distance of about 100 meters. However, it is much less susceptible to EMI and eavesdropping. -The reduced inteference allows for higher bandwidth, potentially as high as 500 Mbps. +STP cable is similar to UTP, but inclues a foil or wire mesh shield between the wire pairs and the outer insulation. The shield is electrically grounded, and reduces emissions and susceptibility to EMI. STP cable is used in some Token Ting and AppleTalk networks. STP is more expensive than +UTP, and its thickness and rigidity make it more difficult to install. It also uses grounded connection connectors, adding to the expense. STP uses the same copper wires as UTP as the same level of attenuation, and therefore the same maximum distance of about 100 meters. However, it is much less susceptible to EMI and eavesdropping. The reduced inteference allows for higher bandwidth, potentially as high as 500 Mbps. Coaxial -Coaxial Cable consists of a single thick copper wire surrounded by an insulator. A shield surrounding -the insulator is used as the second conductor, and is encased in an outer insulation. One type of -coaxial cable is that used for cable television. +Coaxial Cable consists of a single thick copper wire surrounded by an insulator. A shield surrounding the insulator is used as the second conductor, and is encased in an outer insulation. One type of coaxial cable is that used for cable television. The shielding cable makes coaxial cable less susceptible to EMI and emissions than UTP. The cable used in most nteworks is either Thick Ethernet (RG-8) or Thin Ethernet (RG-58). Thin coaxial cable is less expensive than the highest quality (Category 5) UTP, but is more difficult to install due to its thickness, its lack of flexibility, the connectors (you should keep the length of cable between the `T piece' and the actual ethernet card in the PC as short as possible, ideally the `T piece' will be plugged directly into the ethernet card), and the neccesity for terminators (a terminator is a 52 ohm resistor that helps to ensure that the signal is absorbed and not reflected when it reaches the end of the cable. Without a terminator at each end of the cabling you may find that the ethernet is unreliable or doesn't work at all). -The shielding cable makes coaxial cable less susceptible to EMI and emissions than UTP. The cable used -in most nteworks is either Thick Ethernet (RG-8) or Thin Ethernet (RG-58). - -Thin coaxial cable is less expensive than the highest quality (Category 5) UTP, but is more difficult -to install due to its thickness, its lack of flexibility, and the connectors. The generally available types -of coaxial cable are described in the table below. +The generally available types of coaxial cable are described in the table below. Type Impendance Common Cable RG-8 50 ohms Thick Ethernet (thicknet) @@ -75,72 +49,35 @@ RG-62 93 ohms ARCnet Fiber Optic -A fiber optic cable consists of a thin glass or clear plastic fiber encased in a protective jacket. -Signals are sent through the cable in form of light. - -There are two types of fiber optic cable: single-mode, which uses a single wavelength, and multimode, -which uses multiple multiple wavelengths in the same cable. - -Fiber optic cable is completely invulnerable to EMI, and has no detectable emissions, It and its -associated equipment are expensive compared to other types of cable, and the most difficult to install. -Single-mode cable is much more expensive than multimode cable. - -The advantages of fiber are high bandwidth (up to 2 Gbps (gigabits per second) and extremely low -attenuation. Fiber cable can reach distances ranging from severak miles for multimode cable to -hundreds of miles for single-mode cable. +A fiber optic cable consists of a thin glass or clear plastic fiber encased in a protective jacket. Signals are sent through the cable in form of light. There are two types of fiber optic cable: single-mode, which uses a single wavelength, and multimode, which uses multiple multiple wavelengths in the same cable. Fiber optic cable is completely invulnerable to EMI, and has no detectable emissions. However, it and its associated equipment are expensive compared to other types of cable, and the most difficult to install. Single-mode cable is much more expensive than multimode cable. The advantages of fiber are high bandwidth (up to 2 Gbps (gigabits per second) and extremely low attenuation. Fiber cable can reach distances ranging from severak miles for multimode cable to hundreds of miles for single-mode cable. Infrared -Wireless infrared networking systems are modulated beams of infrared light -to transmit data. These types of networks require a line of sight, and are generally used for short -distances such as networks within buildings or between nearby buildings. +Wireless infrared networking systems are modulated beams of infrared light to transmit data. These types of networks require a line of sight, and are generally used for short distances such as networks within buildings or between nearby buildings. Infrared communications are not subject to EMI, but are vulnerable to obstructions (such as weather conditions) and bright light, and suseceptible to eavesdropping. There are two types of infrared networks: -Infrared communications are not subject to EMI, but are vulnerable to obstructions (such as weather conditions) -and bright light, and suseceptible to eavesdropping. There are two types of infrared networks: +- Point-to-point networks use a focused beam, usually generated by a laser. They are less vulnerable to dispersion and can theorectically be used for long distance networking, although the need for precise alignment between receiever and transmitter and the vulneraibility to obstructions often makes it impractical. Bandwidth can be as high as 16 Mbps. -- Point-to-point networks use a focused beam, usually generated by a laser. They are less vulnerable -to dispersion and can theorectically be used for long distance networking, although the need for precise -alignment between receiever and transmitter and the vulneraibility to obstructions often makes it impractical. -Bandwidth can be as high as 16 Mbps. - -- Broadcast networks use a less focused beam that disperses rapidly. These systems can transmit to multiple -workstations ar once, but are much more vulnerable to dispersion, limiting their useful distance and bandwidth. -Bandwidth is usually no more than 1 Mbps. +- Broadcast networks use a less focused beam that disperses rapidly. These systems can transmit to multiple workstations ar once, but are much more vulnerable to dispersion, limiting their useful distance and bandwidth. Bandwidth is usually no more than 1 Mbps. Radio -The most common type of wireless networks use radio waves. Tdaio-based networks have -a reasonably high bandwidth, but are very sensitve to EMI and eavesdropping. Also, -many radio frequencies are regulated by the FCC and are unavailable for use without a -license. There are three types of radio links: +The most common type of wireless networks use radio waves. Tdaio-based networks have a reasonably high bandwidth, but are very sensitve to EMI and eavesdropping. Also, many radio frequencies are regulated by the FCC and are unavailable for use without a license. There are three types of radio links: - Low power single frequency -This type of system is best suited for small ares, such as within a building. It uses -a lower-power transmitter on a single radio frequency. The available range is -approximately 30 meters. This is the lowest-cost method of radio networking. Bandwidth -may be as high as 10 Mbps. +This type of system is best suited for small ares, such as within a building. It uses a lower-power transmitter on a single radio frequency. The available range is approximately 30 meters. This is the lowest-cost method of radio networking. Bandwidth may be as high as 10 Mbps. - High power single frequency -This system is also uses a single frequency, but at a higher power. This allows for -a much greater range, often covering an entire metropolitan area. Bandwidth is typically -10 Mbps. The greater range makes this type of network the most vulnerable to eavesdropping. +This system is also uses a single frequency, but at a higher power. This allows for a much greater range, often covering an entire metropolitan area. Bandwidth is typically 10 Mbps. The greater range makes this type of network the most vulnerable to eavesdropping. - Spread-spectrum -These systems use multiple frequencies, primarily to avoid eavesdropping. This is done in -two ways, direct sequence modulation sends packets sequentially over several different -frequencies, while frequency hopping transmission change frequencies at scheduled intervals -known to both ends. Both of these are significantly less vulnerable less vulnerable to EMI -and snooping than other radio networks. +These systems use multiple frequencies, primarily to avoid eavesdropping. This is done in two ways, direct sequence modulation sends packets sequentially over several different frequencies, while frequency hopping transmission change frequencies at scheduled intervals known to both ends. Both of these are significantly less vulnerable less vulnerable to EMI and snooping than other radio networks. Microwave -Another type of wireless network communications uses microwaves, which are similar to radio -waves but at a higher frequency. Higher frequencies are less vulnerable to interference and -snooping, and can provide greater bandwidth. Two common types of microwave networks are in -use: +Another type of wireless network communications uses microwaves, which are similar to radio waves but at a higher frequency. Higher frequencies are less vulnerable to interference and snooping, and can provide greater bandwidth. Two common types of microwave networks are in use: - Terrestial @@ -155,22 +92,12 @@ range. The bandwidth can be as high as 10 Mbps, but the satellite relays cause d may impair real-time communication. These systems are more expensive than wireless communication. - 9. Cables and Cabling +Serial NULL Modem cable - Those of you handy with a soldering iron may want to build your own - cables to interconnect two linux machines. The following cabling - diagrams should assist you in this. - - 9.1. Serial NULL Modem cable - - Not all NULL modem cables are alike. Many null modem cables do little - more than trick your computer into thinking all the appropriate - signals are present and swap transmit and receive data. This is ok but - means that you must use software flow control (XON/XOFF) which is less - efficient than hardware flow control. The following cable provides the - best possible signalling between machines and allows you to use - hardware (RTS/CTS) flow control. +Not all NULL modem cables are alike. Many null modem cables do little more than trick your computer into thinking all the appropriate signals are present and swap transmit and receive data. This is ok but means that you must use software flow control (XON/XOFF) which is less efficient than hardware flow control. The following cable provides the best possible signalling between machines and allows you to use hardware (RTS/CTS) flow control. + + Pin Name Pin Pin Tx Data 2 ----------------------------- 3 Rx Data 3 ----------------------------- 2 @@ -181,13 +108,17 @@ communication. DSR 6 -/ RLSD/DCD 8 ---------------------------/- 20 \- 6 + + - 9.2. Parallel port cable (PLIP cable) +Parallel port cable (PLIP cable) - If you intend to use the PLIP protocol between two machines then this - cable will work for you irrespective of what sort of parallel ports - you have installed. + +If you intend to use the PLIP protocol between two machines then this cable will work for you irrespective of what sort of parallel ports you have installed. + + + Pin Name pin pin STROBE 1* D0->ERROR 2 ----------- 15 @@ -207,62 +138,22 @@ communication. INIT 16* SLCTIN 17* GROUND 25 ----------- 25 + + - Notes: +Notes: - · Do not connect the pins marked with an asterisk `*'. +· Do not connect the pins marked with an asterisk `*'. +· Extra grounds are 18,19,20,21,22,23 and 24. +· If the cable you are using has a metallic shield, it should be + connected to the metallic DB-25 shell at one end only. - · Extra grounds are 18,19,20,21,22,23 and 24. - - · If the cable you are using has a metallic shield, it should be - connected to the metallic DB-25 shell at one end only. - - Warning: A miswired PLIP cable can destroy your controller card. Be - very careful and double check every connection to ensure you don't - cause yourself any unnecessary work or heartache. - - While you may be able to run PLIP cables for long distances, you - should avoid it if you can. The specifications for the cable allow for - a cable length of about 1 metre or so. Please be very careful when - running long plip cables as sources of strong electromagnetic fields - such as lightning, power lines and radio transmitters can interfere - with and sometimes even damage your controller. If you really want to - connect two of your computers over a large distance you really should - be looking at obtaining a pair of thin-net ethernet cards and running - some coaxial cable. - - 9.3. 10base2 (thin coax) Ethernet Cabling - - 10base2 is an ethernet cabling standard that specifies the use of 52 - ohm coaxial cable with a diameter of about 5 millimeters. There are a - couple of important rules to remember when interconnecting machines - with 10base2 cabling. The first is that you must use terminators at - both ends of the cabling. A terminator is a 52 ohm resistor that - helps to ensure that the signal is absorbed and not reflected when it - reaches the end of the cable. Without a terminator at each end of the - cabling you may find that the ethernet is unreliable or doesn't work - at all. Normally you'd use `T pieces' to interconnect the machines, so - that you end up with something that looks like: - - |==========T=============T=============T==========T==========| - | | | | - | | | | - ----- ----- ----- ----- - | | | | | | | | - ----- ----- ----- ----- - - where the `|' at either end represents a terminator, the `======' rep­ - resents a length of coaxial cable with BNC plugs at either end and the - `T' represents a `T piece' connector. You should keep the length of - cable between the `T piece' and the actual ethernet card in the PC as - short as possible, ideally the `T piece' will be plugged directly into - the ethernet card. - - 9.4. Twisted Pair Ethernet Cable - - If you have only two twisted pair ethernet cards and you wish to - connect them you do not require a hub. You can cable the two cards - directly together. A diagram showing how to do this is included in - the Ethernet-HOWTO + +Warning: A miswired PLIP cable can destroy your controller card. Be very careful and double check every connection to ensure you don't cause yourself any unnecessary work or heartache. + + + +While you may be able to run PLIP cables for long distances, you should avoid it if you can. The specifications for the cable allow for a cable length of about 1 metre or so. Please be very careful when running long plip cables as sources of strong electromagnetic fields such as lightning, power lines and radio transmitters can interfere with and sometimes even damage your controller. If you really want to connect two of your computers over a large distance you really should be looking at alternatives such as obtaining a pair of thin-net ethernet cards and running some coaxial cable. + diff --git a/LDP/guide/docbook/Linux-Networking/WaveLAN.xml b/LDP/guide/docbook/Linux-Networking/WaveLAN.xml index fdc35c63..f5b6cd48 100644 --- a/LDP/guide/docbook/Linux-Networking/WaveLAN.xml +++ b/LDP/guide/docbook/Linux-Networking/WaveLAN.xml @@ -9,7 +9,7 @@ the same way. -You can get information on the Wavelan card from Wavelan.com. +You can get information on the Wavelan card from wavelan.com.