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| @spevack | anyway nirik, whenever you are ready, it's all yours | 14:52 | |
|---|---|---|---|
| nirik | well, hopefully everyone had a minute or two to take a quick break. Shall we get started on the next class? | 14:52 | |
| dash123 | yes master | 14:52 | |
| Padhu1 | yes sir | 14:52 | |
| nirik | hello everyone. I'm Kevin Fenzi and will be talking about Fedora networking today. | 14:52 | |
| mahesh | nirik hello | 14:53 | |
| nirik | this is another topic that is very large and can be complex, so feel free to ask questions and we can steer the class in the direction everyone is interested in. | 14:53 | |
| Padhu1 | ok nirik | 14:53 | |
| nirik | I'd like to start out by talking about the 2 frameworks that Fedora has for handling your networking. | 14:54 | |
| Padhu1 | m | 14:54 | |
| nirik | First, there is the 'network' service. Many of your may know this as it's been used by fedora for a long time. | 14:54 | |
| nirik | it's a setup using configuration scripts. I will talk about them in more detail in a few. | 14:55 | |
| nirik | Then, in newer fedora versions there is a product called NetworkManager that manages the network setup. | 14:56 | |
| Padhu1 | yes | 14:56 | |
| nirik | It's a program that can read the old network scripts, but can also do some more complex things with wireless and passwords and so forth. | 14:56 | |
| Padhu1 | yeah | 14:56 | |
| jyoti | Are they fundamentally different? I thought one runs above the other? Is it not that? | 14:56 | |
| nirik | finally you can if you choose manage your network manually from the command line using low level tools. I can talk about that as well if there is interest. | 14:56 | |
| l0nwlf | yes , please do so | 14:57 | |
| SSlater | yes | 14:57 | |
| Padhu1 | yes please | 14:57 | |
| ... signoff!#fedora-classroom -> megenius_(Read error: 110 (Connection timed out)) | 14:57 | ||
| nirik | jyoti: they are in fact different. There is overlap in that they can read the same config files. You can if you choose use both of them. ;) | 14:57 | |
| nirik | ok, so lets take things from lowest level to higher then... looking first at command line tools. | 14:58 | |
| Padhu1 | ok | 14:58 | |
| nirik | First of all to assign an IP address to your computer you will need to use either ifconfig or a dhcp client tool. | 14:59 | |
| nirik | ifconfig can be a complex command, but a simple invocation might look like: 'ifconfig eth0 up 192.168.1.10 netmask 255.255.255.0' | 14:59 | |
| nirik | This tells the kernel to bring up the 'eth0' network interface with the ip address 192.168.1.10 and assign it a network mask of 255.255.255.0 | 15:00 | |
| nirik | You can see a lot more info on the things it can do in 'man ifconfig' | 15:00 | |
| nirik | If your network has a dhcp server on it, that would take care of assigning ip addresses, and you could do something like 'dhclient eth0' to ask for an address. | 15:01 | |
| nirik | You can also run a 'ifconfig eth0' for example to get information about your current interface. | 15:01 | |
| Padhu1 | sir, how can i set gateway in static | 15:02 | |
| mahesh | ifconfig etho0 will set a temp ip which will expire within mins i guess right ? | 15:02 | |
| nirik | Padhu1: good question. That brings us to routing... just getting an IP address on your network will allow you to talk to it, but you need a route to tell your kernel where to send traffic that is not for your local network. | 15:02 | |
| mahesh | sorry ifconfig eth0* | 15:03 | |
| nirik | mahesh: no, it will never expire.. you have manually added it, and it will stay. ;) dhcp addresses can expire however, depending on how the server is configured. | 15:03 | |
| ... join!#fedora-classroom -> yunustj(n=yunusf10@fedora/yunustj) | 15:04 | ||
| mahesh | so if i have dhcp configured server, it would expire my ip | 15:04 | |
| nirik | any other questions on ifconfig ? shall I move on to routing ? | 15:04 | |
| jyoti | nirik, even after reboot? | 15:04 | |
| ... leave!#fedora-classroom -> sadfag() | 15:04 | ||
| Padhu1 | How can i make multiple IPs | 15:05 | |
| * l0nwlf have a question ? | 15:05 | ||
| nirik | mahesh: it can, depending on how it's setup. Most of them would expire after a time, but your machine can request a renewed ip... | 15:05 | |
| mahesh | ok | 15:05 | |
| nirik | jyoti: no, that would only last until reboot, good point. | 15:05 | |
| nirik | go ahead l0nwlf | 15:05 | |
| l0nwlf | Can I set my IP, gateway, DNS, subnet-mask all from ifconfig command ? | 15:06 | |
| * nirik notes the higher level tools (network/NetworkManager) make most of this all transparent, but it's good to know whats going on behind the scenes. ;) | 15:06 | ||
| UsamaAkkad | yeah right | 15:06 | |
| nirik | l0nwlf: ifconfig will let you set your IP/subnet mask. The 'route' command will let us see and set the gateway/routing. DNS is in a /etc/resolv.conf file. | 15:07 | |
| Padhu1 | How can i make multiple IPs for single Ethernet card? | 15:07 | |
| UsamaAkkad | Padhu1: you are rushing I guess | 15:07 | |
| nirik | Padhu1: You can setup aliased interfaces. So, simpliest case: 'ifconfig eth0:0 up 192.168.10.10' | 15:07 | |
| Padhu1 | oh | 15:07 | |
| nirik | Padhu1: then you would have a eth0 and an eth0:0 with different ip's. ;) | 15:08 | |
| UsamaAkkad | lets understand the basic thing first | 15:08 | |
| l0nwlf | but there is DNS entry in my ifcfg-eth0 | 15:08 | |
| jyoti | nirik, you know there is no use editing /etc/resolv.conf by hand the changes are not used... the changes get used only when nm modifies it... that is what i experienced... | 15:08 | |
| nirik | l0nwlf: yes, we will get to that. | 15:08 | |
| nirik | jyoti: yep. Changing things behind the tools back means that they can change them again. ;) | 15:08 | |
| nirik | lets move on quickly to route and then talk about network and NetworkManager a bit. | 15:09 | |
| Padhu1 | ok sir | 15:09 | |
| nirik | the route command will show you network routes. I usually use -n with it so it doesn't do any dns lookups and is faster... | 15:09 | |
| nirik | route -n | 15:09 | |
| nirik | when you use ifconfig it will automatically make a network route to your local network | 15:09 | |
| ... signoff!#fedora-classroom -> kulll(Read error: 110 (Connection timed out)) | 15:09 | ||
| nirik | but it doesn't make a default route that tells where to send any traffic thats not going to your network. | 15:10 | |
| nirik | if you run a 'route -n' now you can see you likely have a route at the bottom of the list showing '0.0.0.0... ' | 15:10 | |
| nirik | thats the default route. | 15:10 | |
| l0nwlf | http://www.mibbit.com/pb/z0ENsg | 15:10 | |
| nirik | for example, mine looks like: | 15:11 | |
| nirik | 0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 wlan0 | 15:11 | |
| UsamaAkkad | sorry | 15:11 | |
| nirik | l0nwlf: yeah, so the first one is your network route. Anything in that ip range/subnet goes locally to your network. | 15:11 | |
| nirik | l0nwlf: the next one says anything else should go to that gateway. ;) | 15:11 | |
| ... join!#fedora-classroom -> kulll(n=kulll@203.82.91.34) | 15:12 | ||
| nirik | any questions on routes? You can of course have much more complex routing... | 15:12 | |
| jyoti | I love route -nee :) | 15:12 | |
| Padhu1 | How can i set default gateway? | 15:13 | |
| SSlater | Looks like have no gateway set. How to do that? | 15:13 | |
| nirik | Padhu1 / SSlater: excellent question. ;) | 15:13 | |
| G__81 | Padhu, there is an option in the route command default gw | 15:13 | |
| G__81 | which sets it | 15:13 | |
| nirik | route add default gw 192.168.1.1 dev wlan0 | 15:13 | |
| G__81 | :) | 15:14 | |
| nirik | route can add/delete/change existing routes. The above will add a new default route with that gateway (gw) and using that dev | 15:14 | |
| Padhu1 | only for devices? | 15:14 | |
| nirik | note that if you are using dhclient, most likely it would get the gateway from your dhcp server and setup this route for you. | 15:15 | |
| Padhu1 | oh | 15:15 | |
| SSlater | nirik: I get an error - SIOCADDRT: No such process | 15:15 | |
| nirik | you can leave off the 'dev wlan0' or whatever if you like, route can figure out which device you talk to the gateway over and default to that. | 15:15 | |
| nirik | SSlater: make sure you can reach the gateway ip you are specifying... if not you may need to add a route to it first. | 15:16 | |
| nirik | again, this usually is taken care of for you by the high level tools. | 15:17 | |
| Padhu | SSlater: don't try it now please | 15:17 | |
| nirik | I'll quickly mention DNS is configured in the /etc/resolv.conf file. As jyoti mentioned you don't want to change this if you are using network/NetworkManager as they may change it | 15:18 | |
| l0nwlf | Let's say I'm using eth0 and I created an eth1 file to test the command but it's saying no device | 15:18 | |
| ... join!#fedora-classroom -> foolish(n=foolish@fedora/foolish) | 15:19 | ||
| SSlater | Works now. | 15:19 | |
| nirik | l0nwlf: ifconfig won't let you create a new device. ;) If you only have a eth0 then you only have a eth0. ;) | 15:19 | |
| ... signoff!#fedora-classroom -> SSlater(Read error: 54 (Connection reset by peer)) | 15:19 | ||
| nirik | l0nwlf: you can make a eth0:0 or the like alias interface that uses the same eth0 physical interface if you want tho. | 15:19 | |
| mahesh | but i think etho:1 is possible virtual | 15:19 | |
| l0nwlf | oops , I can't test right now or else I'll get disconnected | 15:19 | |
| mahesh | eth0:1 | 15:19 | |
| ... join!#fedora-classroom -> SSlater(n=simon@124-168-17-4.dyn.iinet.net.au) | 15:19 | ||
| nirik | yeah, carefull testing right now. ;) | 15:20 | |
| ... signoff!#fedora-classroom -> sattam1(Read error: 92 (Protocol not available)) | 15:20 | ||
| nirik | mahesh: yes, you can number it whatever you like in fact... | 15:20 | |
| Padhu1 | nirik: sir, is it possible to alias different class networks? | 15:20 | |
| mahesh | ok | 15:20 | |
| ... join!#fedora-classroom -> GeroldKa(n=GeroldKa@fedora/geroldka) | 15:20 | ||
| nirik | Padhu1: not sure I understand the question... what do you mean by class? | 15:20 | |
| nirik | you can make aliases of any physical device... eth0, wlan0, etc. | 15:21 | |
| G__81 | class a/b/c ? | 15:21 | |
| Padhu1 | 192 series and 172 series IPs in aliases | 15:21 | |
| Padhu1 | exactly | 15:21 | |
| nirik | ah, different networks. sure. You can have eth0 and eth0:0 on different networks just fine. | 15:21 | |
| G__81 | yes if you give the appropriate masks & ip range it will work | 15:22 | |
| nirik | ok, shall we move on to talk about network scripts / config? | 15:22 | |
| mahesh | ok | 15:22 | |
| SSlater | yep. | 15:22 | |
| Padhu1 | what about routes/ gateways | 15:22 | |
| l0nwlf | well Padhu1 you mean Like I have 1 card , and 2 network-set (let's assume one of my hostel and another of my lab) so I can create eth0,etho:0 and manually up/down ? | 15:23 | |
| nirik | Padhu1: you can use 'route' to set those up as well. Note that you can only have one default gateway (well, you can have moree than one, but only one matters) | 15:23 | |
| ... signoff!#fedora-classroom -> ideamonk("Leaving") | 15:23 | ||
| Padhu1 | oh. | 15:23 | |
| nirik | ok, so both network and NetworkManager use some config files to describe your setup. | 15:23 | |
| Padhu1 | m | 15:24 | |
| nirik | these can be found in: /etc/sysconfig/network-scripts/ and /etc/sysconfig/network (a file) | 15:24 | |
| mahesh | if-cfg file | 15:24 | |
| nirik | the network file has some high level info... like what your hostname is, if you want networking enabled and so forth. | 15:24 | |
| nirik | it may also have gateway info in it. | 15:25 | |
| nirik | under /etc/sysconfig/network-scripts/ there will be 'ifcfg-INTERFACENAME' files... so a 'ifcfg-eth0' 'ifcfg-wlan0' ifcfg-eth1' etc. | 15:25 | |
| nirik | Those files describe that specific interface. | 15:25 | |
| Padhu1 | oh. If i have an dhcp? | 15:26 | |
| nirik | They can have a static ip address config, or dhcp | 15:26 | |
| Padhu1 | oh | 15:26 | |
| * G__81 wants everyone to recollect on how an interface is created. this was explained yesterday in netlink session :) | 15:26 | ||
| mahesh | ok | 15:26 | |
| Padhu1 | ok G_81 | 15:26 | |
| nirik | there can also be more info in there like wireless networks, MAC address, etc. | 15:26 | |
| Padhu1 | please cary on | 15:27 | |
| nirik | I'll note now that there is a tool called 'system-config-network' that can manage these files for you. | 15:27 | |
| nirik | in that tool you can add/edit/modify the interfaces. | 15:27 | |
| nirik | in the config files there is a config that would look like: | 15:28 | |
| nirik | NM_CONTROLLED=yes (or no). This is important as it tells if 'network' or 'NetworkManager' should control that interface. | 15:28 | |
| Padhu1 | oh | 15:29 | |
| nirik | The 'network' service reads those config files above and runs on boot. It's disabled by default in favor of NetworkManager in recent fedora versions. | 15:29 | |
| UsamaAkkad | and how to disable networkmanger | 15:29 | |
| UsamaAkkad | once I wanted to use wvdial but I couldnt' | 15:30 | |
| nirik | There are still some cases where you might want network over NetworkManager. | 15:30 | |
| l0nwlf | NM means nmapplet , top right icon ? | 15:30 | |
| ... signoff!#fedora-classroom -> CheekyBoinc("Use Fedora Linux -> fedoraproject.org ++ www.cheekyboinc.de ++") | 15:30 | ||
| nirik | UsamaAkkad: you can set NM_CONTROLLED=no on the interfaces, and 'chkconfig network on' | 15:30 | |
| Padhu1 | nirik: sir, you missed to point out start-up configuration of network | 15:30 | |
| l0nwlf | I use network over network manager , because my settings were all grayed out , don't know why ? | 15:30 | |
| UsamaAkkad | thanks | 15:31 | |
| nirik | l0nwlf: yes, the nm-applet talks to NetworkManager, will get to that in a few. ;) | 15:31 | |
| UsamaAkkad | is there record for this channel? | 15:31 | |
| nirik | Padhu1: yeah, network is disabled by default. If you want to start it up, you can use chkconfig or system-config-services to enable it. | 15:31 | |
| UsamaAkkad | I've to go | 15:31 | |
| nirik | UsamaAkkad: yep. ;) will be a log. | 15:32 | |
| UsamaAkkad | nice, where ? | 15:32 | |
| nirik | on the wiki page in the topic. ;) Linked to the class name. | 15:32 | |
| Padhu1 | oh | 15:32 | |
| SSlater | Does Fedora use an /etc/network/interfaces file? | 15:32 | |
| Padhu1 | SSlater: no | 15:32 | |
| nirik | SSlater: it does not... the config is under /etc/sysconfig/network-scripts/ | 15:32 | |
| SSlater | Ok. | 15:33 | |
| nirik | ok, any questions on network service before I move on to NetworkManager? | 15:33 | |
| Padhu1 | SSlater: you are talking about debian or its derivatives | 15:33 | |
| ... signoff!#fedora-classroom -> UsamaAkkad("bye") | 15:33 | ||
| Padhu1 | no questions | 15:33 | |
| Padhu1 | wireless services | 15:34 | |
| nirik | note that NetworkManager can/will read the same /etc/sysconfig/network-scripts/ config files as network... unless NM_CONTROLLED=no (then it ignores that interface) | 15:34 | |
| nirik | ok, NetworkManager is a new service that handles networking. | 15:34 | |
| nirik | It's got advantages over network in many cases. It can handle wireless networks with passphrases and cases such as that, as well as the normal cases. | 15:34 | |
| nirik | it runs in the background watching your network setup and communicates to you via the 'nm-applet' applet in your system tray. | 15:35 | |
| ... signoff!#fedora-classroom -> GeroldKa(Remote closed the connection) | 15:35 | ||
| Padhu1 | m | 15:35 | |
| nirik | From there you can join wireless networks, enable/disable wired connections, or connect to cell data cards, etc. | 15:36 | |
| l0nwlf | nirik: one question , In my case I had set IP and other settings in NM but when I checked for ifcfg-eth0 files , there was nothing ? Is it true that NM takes the setting from same file | 15:36 | |
| nirik | l0nwlf: it can. It can also store them internally. It depends on how you made the config. If it's with nm-applet, it will store it internally by default. | 15:36 | |
| Padhu1 | l0nwlf:: just restart the network service | 15:37 | |
| ... join!#fedora-classroom -> ranna(n=ranna@user-0c8h9pu.cable.mindspring.com) | 15:37 | ||
| nirik | if you use system-config-network to do it it will save it in the ifcfg type files. | 15:37 | |
| l0nwlf | i made it with nm-applet , so it must store it internally | 15:37 | |
| nirik | I'd like to touch on some nice features of NetworkManager/tools for it. | 15:37 | |
| nirik | One nice one is the 'nm-tool' command. | 15:37 | |
| Padhu1 | oh | 15:38 | |
| nirik | this will show you the config of NetworkManager. You can see what states all it's interfaces are in and if they are managed, etc. | 15:38 | |
| Padhu1 | in terminal? | 15:38 | |
| nirik | yes, it's a terminal/command line command. | 15:38 | |
| nirik | here is my output: http://fpaste.org/paste/8024 | 15:39 | |
| nirik | so you can see I have a eth0, but it's not connected, a wiress that is connected and active, and a mobile broadband thats not connected. | 15:39 | |
| nirik | nm-tool is handy when trying to see what your current network state is. | 15:40 | |
| ... signoff!#fedora-classroom -> openpercept("Leaving") | 15:40 | ||
| ... signoff!#fedora-classroom -> indSpike("Leaving.") | 15:40 | ||
| Padhu1 | yes. i saw the link | 15:40 | |
| nirik | There are a lot of things you can configure in the nm-applet tool as well. You can in there edit connections and set various things on them. | 15:40 | |
| Padhu1 | please tach us | 15:41 | |
| Padhu1 | teach | 15:41 | |
| nirik | if you right click on the applet it should give you a 'edit connections' option. | 15:41 | |
| nirik | then it should pull up an editor. You can see the wired/wireless/etc tabs. | 15:41 | |
| Padhu1 | oh | 15:42 | |
| mahesh | yes | 15:42 | |
| Padhu1 | yeah | 15:42 | |
| nirik | you can set things under each interface like dns servers you would like, etc. | 15:42 | |
| nirik | For wireless you can set if you want to connect to that network automatically or not and other items. | 15:43 | |
| mahesh | to make things easy i always select auto eth0 in that applet | 15:43 | |
| Padhu1 | +1 | 15:43 | |
| nirik | NetworkManager also has some plugins for VPN. If you have those installed, you can configure a virtual private network in there as well. | 15:43 | |
| mahesh | ok | 15:44 | |
| nirik | we are starting to run low on time, so any questions on anything so far? | 15:44 | |
| nirik | this is really a big topic. ;) | 15:44 | |
| mahesh | keep going | 15:45 | |
| G__81 | :) its got networking which is a big topic by itself and its also got fedora's tools :) which is an other big topic :) | 15:45 | |
| nirik | can do. ;) | 15:45 | |
| Padhu1 | no questions. please carry on | 15:45 | |
| nirik | ok, a quick note about startup with NetworkManager. | 15:45 | |
| nirik | It will start on boot and configure any networks you have ifcfg- scripts for. | 15:45 | |
| Padhu1 | yes | 15:45 | |
| nirik | just like network. | 15:45 | |
| nirik | However, it cannot join you to wireless networks on boot, you must login. This is due to it using your users keyring to store any passphrases you need to join those wireless networks. | 15:46 | |
| ... join!#fedora-classroom -> GeroldKa(n=GeroldKa@fedora/geroldka) | 15:46 | ||
| nirik | So, if you are using wireless and it doesn't come up on boot, you need to remember to login. :) | 15:47 | |
| Padhu1 | oh | 15:47 | |
| mahesh | ok | 15:47 | |
| ... signoff!#fedora-classroom -> jyoti(Remote closed the connection) | 15:47 | ||
| nirik | as I mentioned eariler you can also use both if you want. Use system-config-network and/or edit the ifcfg- files to use the NM_CONTROLLED value to see which one controls which interrface. | 15:48 | |
| nirik | oh, another nice thing with NetworkManager I wanted to mention. | 15:48 | |
| nirik | If you want to run some script when you connect/disconnect to a network, you can make a script and place it in /etc/NetworkManager/dispatcher.d/ | 15:49 | |
| nirik | NM will read scripts in there and run them on connect/disconnect. | 15:49 | |
| Padhu1 | one example please | 15:49 | |
| nirik | if you take a look in there, you likely have a few system provided ones. Let me give an example tho | 15:49 | |
| nirik | sendmail places a simple one in there that looks like: | 15:50 | |
| nirik | #!/bin/sh | 15:50 | |
| nirik | if [ "$2" = "up" ] | [ "$2" = "down" ]; then | 15:50 |
| nirik | /sbin/service sendmail reload | : | 15:50 |
| nirik | fi | 15:50 | |
| nirik | you can see the script is passed 'up' or 'down' if the network is being connected/disconnected. | 15:51 | |
| nirik | you can run a particular action on that. | 15:51 | |
| Padhu1 | oh. | 15:51 | |
| nirik | this is handy if you have some resource you want to connect to on ever network connection. | 15:51 | |
| Padhu1 | How to watch out IP conflicts? | 15:52 | |
| nirik | Padhu1: good question. There is some automatic detection of conflicts... so if you use network or NM it will tell you and refuse to use the ip. | 15:52 | |
| nirik | if you manually use ifconfig you may bypass the detection. | 15:53 | |
| nirik | if you use dhcp your dhcp server should handle all that. | 15:53 | |
| mahesh | ok | 15:53 | |
| Padhu1 | Is it display the MAC Addess of ethernet device which is already have the same ip? | 15:53 | |
| nirik | yes, it would. | 15:54 | |
| Padhu1 | oh | 15:54 | |
| ... signoff!#fedora-classroom -> G__81("Leaving") | 15:54 | ||
| ... signoff!#fedora-classroom -> kulll(Read error: 110 (Connection timed out)) | 15:54 | ||
| nirik | another nice feature NetworkManager has is if you are on wired and have a wireless card. You can share your connection to users on wireless. | 15:54 | |
| Padhu1 | m | 15:55 | |
| nirik | simply left click on the nm-applet and select 'create new wireless network'. Give it a name and say ok. | 15:55 | |
| nirik | then other wireless uses should see it and be able to use your machine as their gateway. | 15:55 | |
| Padhu1 | you mean proxy? | 15:55 | |
| nirik | it will act as a default gateway and send all their traffic to/from the wired connection. | 15:56 | |
| Padhu1 | or router | 15:56 | |
| Padhu1 | oh | 15:56 | |
| * nirik sees we are somewhat out of time now. | 15:56 | ||
| nirik | any last minute questions on any networking items? | 15:56 | |
| SSlater | DHCP next month? | 15:57 | |
| Padhu1 | SSlater: DHCP Server? | 15:57 | |
| ... join!#fedora-classroom -> sattam(n=sattam@unaffiliated/thtoh) | 15:57 | ||
| nirik | we could do a dhcp class... both client and server setup would be interesting. | 15:57 | |
| ... join!#fedora-classroom -> kulll(n=kulll@203.82.79.2) | 15:57 | ||
| Padhu1 | oh. | 15:57 | |
| mahesh | sure | 15:57 | |
| SSlater | Could have used it last week ... have to wait. | 15:58 | |
| nirik | anyhow, thanks for coming everyone. :) Feel free to ask any further networking questions over in #fedora, or here if you like. ;) | 15:58 | |
| @spevack | nirik: thanks for running the class! | 15:58 | |
| nirik | no problem. Happy to teach. | 15:59 | |
| Padhu1 | nirik: THank you sir. | 15:59 | |
| SSlater | Thank you nirik! | 15:59 | |
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