Howto: Ethernet connection without a GUI

[Detonate]

Recently there seems to have been a lot of posters with problems getting their internet connection working with a wired connection. Many of these problems seem to be related to the network manager not working correctly. This could be Knetworkmanager, in Kubuntu 8.04 and earlier, and network-manager-kde in 8.10.

It's nice to have a GUI to help with setup of things, but sometimes they just don't seem to work. In fact, sometimes they actually break a working system. So I'm going to explain, step-by-step how to get things working for your network and internet without using the GUI.

First thing you should do is remove any network managers you have installed. The reason we remove them is because, once you get your network up and running, those programs will try change things in the files we are going to edit, and possibly break things again. Open a terminal and, depending on your version of Kubuntu, issue one of these commands.

For 8.10


sudo apt-get remove network-manager-kde


sudo apt-get remove network-manager

For 8.04 and earlier


sudo apt-get remove network-manager-kde


sudo apt-get remove knetworkmanager


sudo apt-get remove network-manager

And remove any other networking managers you may have installed.

Now we need to make sure that your system is actually recognizing your ethernet hardware.
Issue the command
ifconfig in a terminal, and you will quickly see what interfaces are currently active. Hopefully you will see at least eth0 and lo listed. If not, you need to get eth0 working, and that is beyond the scope of this howto. Search the forum for information on getting your network card up and running, then come back here.

Next you will need to edit two files. The /etc/network/interfaces file and the /etc/resolv.conf file. Be sure and back up both files before editing them.

Open the interfaces file by issuing the command kdesudo kate /etc/network/interfaces in a terminal. When kate opens you should see something like this.
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

# The loopback network interface
auto lo
iface lo inet loopback
address 127.0.0.1
netmask 255.0.0.0

# The primary network interface
auto eth0
iface eth0 inet dhcp
If your file doesn't look like this, edit it. Then save the file. You should now be able to connect to a dhcp server, which is your router or cable/dsl modem if you are not using a router. This setup will get you running with DHCP. If you want to use a static IP on your network, you would change the line
iface eth0 inet dhcp
to read
iface eth0 inet static

and then enter the following lines below that.
address 192.168.1.10
netmask 255.255.255.0
gateway 192.168.0.1

Modify these lines for your system. The address must be one that will be recognized by your router and outside the DHCP address your router assigns, if DHCP is enabled in you router.

The gateway also must be the gateway of your router.

The following info is only for using a static IP. If you are using dhcp you should not have to edit the resolv.conf file.


But before you get connected, we need to tell your computer where to find the domain name server. (DNS)

That is the function of the /etc/resolv.conf file.

So let's open up that file with kate (or any text editor) by issuing the command kdesudo kate /etc/resolv.conf in a terminal. If there is no resolv.conf you will be presented with a blank page. If one already exists you will see something like this. Saving your file will modify or create the resolv.conf file.

This is what mine looks like.

nameserver 208.67.222.222
nameserver 208.67.220.220
nameserver 192.168.0.1

You can have up to three nameservers listed in resolv.conf. These are the places where information is stored that resolves urls into IP addresses. The first two listed above are for OpenDNS which is the DNS server I have been using for a long time. The last one is for my router where information is kept to allow you to access other computers on your network.

In your file, you want to put the nameserver (DNS) that matches the one listed in your router or modem. You will need to access the setup page from a browser to find out exactly what that is. You can find out how to do this by consulting you router or modem documentation.

Here's a shot of the page in my router's setup that shows us the info we need.

http://img25.imageshack.us/img25/8974/routerinfo.th.png (http://img25.imageshack.us/i/routerinfo.png/)

Uploaded with ImageShack.us (http://imageshack.us)

Edit your file to include those DNS's listed in your router's or modems setup, preceded by the word "nameserver" before each. Save the file (you did make a backup earlier didn't you)?

Now we are ready to see if it works. Issue the following command in a terminal.


sudo /etc/init.d/networking restart

See:
man interfaces
man resolv.conf

Note: I used the command kdesudo but in you have KDE 3.5.* you will use kdesu instead. And when I said "router" that could also refer to your modem if you are connected directly without a router. And of course you can substitute any text editior for "kate".

Please feel free to point out any mistakes or other helpful hints.

[Snowhog]

Good post. I'm sure this will be very helpful for those who find themselves in 'Inter(not) hell' and are unable to get connected to the Internet.

It should be stressed (for those who won't know otherwise) that this is for connecting via a wired connection.

[toad]

Great stuff, Detonate - you delivered right on time ;D

[gandalf99]

detonate--

This is really a gift. Thank you. Fortunately, my wired connection works fine. It would be great if someone could do this for wifi.

[Detonate]

There's no reason this should not work for your wireless connection, but you need to make sure your wireless device is working first, then you need to put in the essid and key if it is a secured network. If you are using wireless on only one network, it's not to hard. But on a traveling laptop, you really need a network manager (I use wicd) to help you get connected.

[froebi]

Hi,

thanks for this post. At least it got me connected it again. Ever since this network manager stuff got introduced, I'm having problems with that connection stuff. And with Intrepid things got even worse. I wonder how they could release it this way. Two core functionalities -- namely networking and package management (i.e. adept) -- are completely broken in Intrepid. I've seen this kind of development with SuSE already. That's what made me switch to (k)ubuntu back then.

Ok, but back to the topic. Now I have my laptop's eth0 interface configured to use dhpc as described. But now when I boot the laptop and have no cable plugged in, the boot hangs for a long time. -- Is there some way around this? I think what I'm asking for is some kind of hot-plug mechanism (Or is this exactly what the network manager is supposed to be responsible for?).

Thanks,
Christian

[Detonate]

When Kubuntu boots up, during the boot process it automatically tries to establish a network connection. That's what takes so long to boot when you don't have the cable plugged in. If you want to watch the boot process you can edit the /boot/grub/menu.lst file and remove the words quiet and splash from the kernel line. Then when you boot up you will get to watch all the things that happen during boot, and if it hangs, you'll know where. I'm not sure how to make it skip the networking part unless you remove networking from init.d, but then you would have to go replace it every time you wanted to boot with networking. I have the same problem because sometimes when I boot up, one of my other computers is not on, and *ubuntu can't find the NFS shared folders. Unless someone else has a better idea, I would say, learn to live with it. ;D ;D

[froebi]

Hi,

after some research in the different forums I found a fix that works. And by working I mean
* I can hot-plug a cable in eth0 wich is then configured via DHCP
* I can use WLAN
* And all this with this crappy KNetworkManager

All I had to do was to wipe out almost everything in /etc/network/interfaces leaving it with the bare essentials:


auto lo
iface lo inet loopback


Reboot and you're done. All of the sudden KNetworkManager works quite fine now.

Maybe this helps someone.

Christian

[dibl]

@Detonate, somehow I had missed this excellent How-To -- I'm linking to it in the "Top 20 FAQ's.

Thanks! :)

[The_Fury]

Hopefully you will see at least eth0 and lo listed.


Why would it be listed still, by removing those 2 packages you have just knocked out the eth0 as well. A little testing might have been an good idea as i now have to find out how to get eth0 being detected by ifconfig. Which was there prior to following your instructions.

And of course i cannot install them again either as i have no network connection for apt to be able to install from the repo. Thanks, but this tute is a big fail so far.

Now maybe you might like to tell me how to get eth0 working again, and put that into your tute to make it not so much fail

[Snowhog]

I strongly suggest that you re-read it again - completely. It would also be a good idea to print it out - fully.

Detonate has spent a lot of time helping, not only himself with this, but others as well, before he decided to put the HOWTO together. When followed correctly, it does work.

[Detonate]

Removing the network manager programs does nothing to remove the actual network interface devices from your system. If you can not find any network device with ifconfig you have a problem not related to my howto. I suspect that you may have inactivated the interface with one of the network manager programs before you uninstalled them. To check and see if the interface is installed, but not active, you can enter
ifconfig -a in a terminal. The -a option will cause ifconfig to list all interfaces, even if inactive. If you see eth0 then, you should be able to make it active by entering
sudo ifup eth0.

[reggler]

hm i removed the network-manager(-kde) and then all that was left over was the lo :( I disdn't know what to do I just reinstalled the network-manager (-kde) but of course apt-get couldn't download anything as i had only lo left...I was like "CRAP!!!" and out of desperation I just rebooted (I had /etc/init.d/network restart tried before) after the reboot i had this available again:


eth0 Link encap:Ethernet HWaddr 00:1c:25:03:b0:f3
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
Memory:effc0000-effe0000

eth1 Link encap:Ethernet HWaddr 00:e0:29:84:a3:bb
inet addr:192.168.0.240 Bcast:192.168.0.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1464 Metric:1
RX packets:63276 errors:0 dropped:0 overruns:0 frame:0
TX packets:43350 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:52186259 (52.1 MB) TX bytes:4511878 (4.5 MB)
Interrupt:17 Base address:0xbe00

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:1799 errors:0 dropped:0 overruns:0 frame:0
TX packets:1799 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:54763 (54.7 KB) TX bytes:54763 (54.7 KB)

How did this happen? I also believe this is still going with the network-manager as I get this:


reg@reg-desktop:~$ cat /etc/network/interfaces
auto lo
iface lo inet loopback

I'm not quite sure how I shoudl proceed from here... it's a little risky to remove the nwetwork manager and then end-up without any network interfaces.... :o
also now apt-get keeps telling me:


network-manager is already the newest version.
The following packages were automatically installed and are no longer required:
linux-headers-2.6.27-7 linux-headers-2.6.27-7-generic
Use 'apt-get autoremove' to remove them.
0 upgraded, 0 newly installed, 0 to remove and 1 not upgraded.

So network-manager is apparenrtly still installed and under control - i don't even dare to run a apt-get autoremove cause i'm afraid to end up without something i really need (network connection)...

How should i proceed?

Thanks!

[dibl]

How should i proceed?



What are you trying to do? It looks like your network setup is perfect, from here. ???

[Detonate]

Looks OK to me too, as a very wise man once said,

"If it ain't broke, don't fix it"!

[Snowhog]

And as a wiser man (might have) said:

"If it's working, why try to break it?" ;D

[toad]

Well, that IS why we have Linux, isn't it? To live and learn, to break and fix... I just wish I could do some more fixing and less breaking :)

[Detonate]

I plead guilty to being a person who often violates the "If it ain't broke rule". ;D ;D

[toad]

The beauty of Linux is that you can break it yourself rather than it breaking itself (which a certain other OS whose name escapes me at the mo is quite an expert in) - makes quite a difference 8)

[dibl]

I plead guilty to being a person who often violates the "If it ain't broke rule". ;D ;D


Is that the one that says "If it ain't broke, you must try to improve it!"? That's my favorite rule! ;D

[Snowhog]

or, "If it aint broke, try harder." ;D

[Detonate]

So yesterday I decided to install kubuntu-desktop on my Xubuntu 8.10 install and for some reason it broke firefox. No window decoration. Took me two hours to fix it.

[Cardcaptor Stacey]

Hi. I wonder if you could help me please.

I've just gone through your tutorial but the internet is still not working. I just don't know what to do anymore. Been trying to fix this for over a week without no luck. :( I'm left to browse the internet on my Wii because this is the only thing that works!

[Detonate]

OK, if I had a Wii I would not have time to help you. I would be playing golf all day. :)

Let's start by making sure your machine sees it's ethernet device. Run

ifconfig -a

in a terminal, and post the results.

Ditto for

cat /etc/network/interfaces

Is your computer hooked to a router or directly to a cable or dsl modem?

[Cardcaptor Stacey]

Hi. Thank you so much for getting back to me so quickly. :) I had to manually copy all this data to my Wii... Excuse any typos

eth0 Link encap:Ethernet HWaddr 00:1e:68:ac:69:6f
inet6 addr: fe80::21e:68ff::feac:696f/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:671088600 overuns:0 frame:0
TX packets:0 errors:0 dropped:779 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0B) TX bytes:0(0.0B)
Interrupt:219

eth0:avahi Link encap:Ethernet HWaddr 00:1e:68:ac:69:6f
inet addr:169.254.6.194 Bcast:169.254.255.255 Mask:255.255.0.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
Interrupt:219

lo Link encap:Local loopback
inet addr:127.0.0.1 Mask 255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX Packets:394 errors:0 dropped:0 overruns:0 frame:0
TX Packets:394 errors:0 dropped:0 overruns:0 carrier:0 collisios:0 txqueuen:0
RX bytes:22176(33.1KB) TX bytes:33176 (33.1KB)

auto lo
iface lo inet loopback
address 127.0.0.1
netmask 255.0.0.0

auto eth0
iface eth0 inet dhcp

Laptop is hooked up to a proxy. I have tried using iface eth0 inet static with my network details but didn't work either.

[Detonate]

Do you see the eth0:avahi that shows an IP address of 169.254.6.194? That means the computer was unable to find a DHCP server and it uses that address so that it can continue, but it is not a true internet connection.

The problem is in the settings you need to connect through your proxy, and I have no experience with that. How do you have your Wii connected? Who runs the proxy? Can they provide you with the information needed to connect?

[Cardcaptor Stacey]

My Wii (I think) is directly connected to the internet. My brother set up the proxy. I do have the connection details but I'm not too sure if I need DHCP or static. Static you can give information but DHCP I'm not so sure. Maybe if I tried researching proxies. Thanks for your help. I'll see what I can find.

[Cardcaptor Stacey]

Been researching and it should just connect through DHCP. So what should I do?

[Detonate]

I'm not sure. One thing is that proxies work through a specific port, and that port has to be open for it to work. Do you know what port the proxy you are trying to use requires to be open?

[Cardcaptor Stacey]

Using the same data as I did before. There's nothing wrong...but look at how many of my packets have dropped. 452000000. :S Is this more of a serious problem?

[kyonides]

Earlier this year some user said...





Hopefully you will see at least eth0 and lo listed.


Why would it be listed still, by removing those 2 packages you have just knocked out the eth0 as well. A little testing might have been an good idea as i now have to find out how to get eth0 being detected by ifconfig. Which was there prior to following your instructions.

And of course i cannot install them again either as i have no network connection for apt to be able to install from the repo. Thanks, but this tute is a big fail so far.

Now maybe you might like to tell me how to get eth0 working again, and put that into your tute to make it not so much fail

I must say that this guide actually helped me a lot by bringing my internet connection back to life. Of course, you'd need some Distro Install CD before you uninstall network-manager(-kde).

[seangee]

I must say that this guide actually helped me a lot by bringing my internet connection back to life. Of course, you'd need some Distro Install CD before you uninstall network-manager(-kde).

Worked fine for me and I never had to install anything. It doesn't knock anything out. Initially I couldn't bring up eth0 because I had blindly copied the address and was on the incorrect subnet. sudo ifconfig -a proved the device existed so all I had to do was trace the typo 8)

[NMY]

Please edit the main post with:

auto lo
iface lo inet loopback

auto eth0
iface eth0 inet static
address <your ip address>
netmask <your netmask>
gateway <your gateway>

[kevinc]

Hi,

after some research in the different forums I found a fix that works. And by working I mean
* I can hot-plug a cable in eth0 wich is then configured via DHCP
* I can use WLAN
* And all this with this crappy KNetworkManager

All I had to do was to wipe out almost everything in /etc/network/interfaces leaving it with the bare essentials:


auto lo
iface lo inet loopback


Reboot and you're done. All of the sudden KNetworkManager works quite fine now.

Maybe this helps someone.

Christian



Very interesting. My Jaunty worked perfectly with dhcp until I tried to connect PPPoE and couldn't get it to work, then followed instructions which stopped everything from working. Going back to my dual boot Intrepid I find the /etc/network/interfaces is exactly as you mention and it works nicely with wireless and dhcp. As I need at least one working system, I'm not going to touch it until I get my Jaunty working. I've spend hours finding lots of information but nothing that has helped, yet. When I do manage to, I'll add to the post.

[pdaalder]

Hi I've been reading this topic, and I've tried what you suggested, but unfortunately it didn't deliver what I was looking for.

My interfaces file (/etc/network/interfaces) is like:


auto lo
iface lo inet loopback

auto eth0
iface eth0 inet dhcp
[quote]

doing ifconfig returns a similar list as another poster (both eth0 and eth0:avahi). I'm not using a proxy, but just a direct conection to the ethernet cable. I know there is a connection, as I have with the same cable a connection on my other machine. I upgraded (completely reinstalled kubuntu 9.04 today, so formated partitions) today, and since today it stopped.

The machine is a Dell D820, with a Broadcom NetXtreme GB card. Any tip, never expected installing would be so stressfull. I wished I was paid by hour for this :-(.

[quote=Detonate ]
Do you see the eth0:avahi that shows an IP address of 169.254.6.194? That means the computer was unable to find a DHCP server and it uses that address so that it can continue, but it is not a true internet connection.

The problem is in the settings you need to connect through your proxy, and I have no experience with that. How do you have your Wii connected? Who runs the proxy? Can they provide you with the information needed to connect?

[Detonate]

See if you can get connected by running:

sudo dhclient eth0

in a terminal.

[pdaalder]

no luck, also tried what this article says:
http://www.prash-babu.com/2009/05/how-to-fix-ip-by-dhcp-issue-in-ubuntu.html

but no luck.

Any other thinks I can try.

[pdaalder]

oh, just so you know, I've downloaded today the version, and it is using linux 2.6.28.11-generic

[Detonate]

When you ran the dhclient command, what was the output?

[pdaalder]

pdaalder@D820:~$ sudo dhclient eth0
Internet Systems Consortium DHCP Client V3.1.1
Copyright 2004-2008 Internet Systems Consortium.
All rights reserved.
For info, please visit http://www.isc.org/sw/dhcp/

wmaster0: unknown hardware address type 801
wmaster0: unknown hardware address type 801
Listening on LPF/eth0/00:15:c5:09:c5:5a
Sending on LPF/eth0/00:15:c5:09:c5:5a
Sending on Socket/fallback
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 4
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 9
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 12
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 19
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 7
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 10
No DHCPOFFERS received.
No working leases in persistent database - sleeping.




pdaalder@D820:~$ sudo more /etc/network/interfaces
auto lo
iface lo inet loopback

iface eth0 inet dhcp
auto eth0


Note:this file wasn't there I've created it manually


root@D820:~# more /etc/resolv.conf
nameserver 208.67.222.222
nameserver 208.67.220.220




root@D820:~# more /proc/version
Linux version 2.6.28-11-generic (buildd@palmer) (gcc version 4.3.3 (Ubuntu 4.3.3-5ubuntu4) ) #42-Ubuntu SMP Fri Apr 17 01:57:59 UTC 2009




root@D820:~# /etc/init.d/networking restart
* Reconfiguring network interfaces...There is already a pid file /var/run/dhclient.eth0.pid with pid 3652
killed old client process, removed PID file
Internet Systems Consortium DHCP Client V3.1.1
Copyright 2004-2008 Internet Systems Consortium.
All rights reserved.
For info, please visit http://www.isc.org/sw/dhcp/

wmaster0: unknown hardware address type 801
wmaster0: unknown hardware address type 801
Listening on LPF/eth0/00:15:c5:09:c5:5a
Sending on LPF/eth0/00:15:c5:09:c5:5a
Sending on Socket/fallback
Internet Systems Consortium DHCP Client V3.1.1
Copyright 2004-2008 Internet Systems Consortium.
All rights reserved.
For info, please visit http://www.isc.org/sw/dhcp/

wmaster0: unknown hardware address type 801
wmaster0: unknown hardware address type 801
Listening on LPF/eth0/00:15:c5:09:c5:5a
Sending on LPF/eth0/00:15:c5:09:c5:5a
Sending on Socket/fallback
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 3
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 3
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 8
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 9
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 9
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 10
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 10
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 9
No DHCPOFFERS received.
No working leases in persistent database - sleeping.

root@D820:~# ifdown eth0
There is already a pid file /var/run/dhclient.eth0.pid with pid 4048
killed old client process, removed PID file
Internet Systems Consortium DHCP Client V3.1.1
Copyright 2004-2008 Internet Systems Consortium.
All rights reserved.
For info, please visit http://www.isc.org/sw/dhcp/

wmaster0: unknown hardware address type 801
wmaster0: unknown hardware address type 801
Listening on LPF/eth0/00:15:c5:09:c5:5a
Sending on LPF/eth0/00:15:c5:09:c5:5a
Sending on Socket/fallback

root@D820:~# ifup eth0
Internet Systems Consortium DHCP Client V3.1.1
Copyright 2004-2008 Internet Systems Consortium.
All rights reserved.
For info, please visit http://www.isc.org/sw/dhcp/

wmaster0: unknown hardware address type 801
wmaster0: unknown hardware address type 801
Listening on LPF/eth0/00:15:c5:09:c5:5a
Sending on LPF/eth0/00:15:c5:09:c5:5a
Sending on Socket/fallback
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 8
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 19
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 19
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 10
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 5
No DHCPOFFERS received.
No working leases in persistent database - sleeping.

root@D820:~# ifconfig
eth0 Link encap:Ethernet HWaddr 00:15:c5:09:c5:5a
inet6 addr: fe80::215:c5ff:fe09:c55a/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:169 errors:0 dropped:0 overruns:0 frame:0
TX packets:47 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:20800 (20.8 KB) TX bytes:8065 (8.0 KB)
Interrupt:18

eth0:avahi Link encap:Ethernet HWaddr 00:15:c5:09:c5:5a
inet addr:169.254.6.145 Bcast:169.254.255.255 Mask:255.255.0.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
Interrupt:18

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:69 errors:0 dropped:0 overruns:0 frame:0
TX packets:69 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:4804 (4.8 KB) TX bytes:4804 (4.8 KB)

pan0 Link encap:Ethernet HWaddr 56:9a:46:95:83:7f
inet6 addr: fe80::549a:46ff:fe95:837f/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:0 (0.0 B) TX bytes:1152 (1.1 KB)

wlan0 Link encap:Ethernet HWaddr 00:13:02:6d:70:c2
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)

wmaster0 Link encap:UNSPEC HWaddr 00-13-02-6D-70-C2-00-00-00-00-00-00-00-00-00-00
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)




root@D820:/etc# lspci
00:00.0 Host bridge: Intel Corporation Mobile 945GM/PM/GMS, 943/940GML and 945GT Express Memory Controller Hub (rev 03)
00:01.0 PCI bridge: Intel Corporation Mobile 945GM/PM/GMS, 943/940GML and 945GT Express PCI Express Root Port (rev 03)
00:1b.0 Audio device: Intel Corporation 82801G (ICH7 Family) High Definition Audio Controller (rev 01)
00:1c.0 PCI bridge: Intel Corporation 82801G (ICH7 Family) PCI Express Port 1 (rev 01)
00:1c.1 PCI bridge: Intel Corporation 82801G (ICH7 Family) PCI Express Port 2 (rev 01)
00:1c.2 PCI bridge: Intel Corporation 82801G (ICH7 Family) PCI Express Port 3 (rev 01)
00:1c.3 PCI bridge: Intel Corporation 82801G (ICH7 Family) PCI Express Port 4 (rev 01)
00:1d.0 USB Controller: Intel Corporation 82801G (ICH7 Family) USB UHCI Controller #1 (rev 01)
00:1d.1 USB Controller: Intel Corporation 82801G (ICH7 Family) USB UHCI Controller #2 (rev 01)
00:1d.2 USB Controller: Intel Corporation 82801G (ICH7 Family) USB UHCI Controller #3 (rev 01)
00:1d.3 USB Controller: Intel Corporation 82801G (ICH7 Family) USB UHCI Controller #4 (rev 01)
00:1d.7 USB Controller: Intel Corporation 82801G (ICH7 Family) USB2 EHCI Controller (rev 01)
00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev e1)
00:1f.0 ISA bridge: Intel Corporation 82801GBM (ICH7-M) LPC Interface Bridge (rev 01)
00:1f.2 IDE interface: Intel Corporation 82801GBM/GHM (ICH7 Family) SATA IDE Controller (rev 01)
00:1f.3 SMBus: Intel Corporation 82801G (ICH7 Family) SMBus Controller (rev 01)
01:00.0 VGA compatible controller: nVidia Corporation G72M [Quadro NVS 110M/GeForce Go 7300] (rev a1)
03:01.0 CardBus bridge: O2 Micro, Inc. Cardbus bridge (rev 21)
03:01.4 FireWire (IEEE 1394): O2 Micro, Inc. Firewire (IEEE 1394) (rev 02)
09:00.0 Ethernet controller: Broadcom Corporation NetXtreme BCM5752 Gigabit Ethernet PCI Express (rev 02)
0c:00.0 Network controller: Intel Corporation PRO/Wireless 3945ABG [Golan] Network Connection (rev 02)


When I plugin the cable and check the system:


root@D820:/# dmesg
[ 1425.809137] tg3: eth0: Link is up at 100 Mbps, full duplex.
[ 1425.809143] tg3: eth0: Flow control is off for TX and off for RX.

root@D820:/# ifdown eth0
There is already a pid file /var/run/dhclient.eth0.pid with pid 4380
killed old client process, removed PID file
Internet Systems Consortium DHCP Client V3.1.1
Copyright 2004-2008 Internet Systems Consortium.
All rights reserved.
For info, please visit http://www.isc.org/sw/dhcp/

wmaster0: unknown hardware address type 801
wmaster0: unknown hardware address type 801
Listening on LPF/eth0/00:15:c5:09:c5:5a
Sending on LPF/eth0/00:15:c5:09:c5:5a
Sending on Socket/fallback

root@D820:/# dmesg
[ 1425.809137] tg3: eth0: Link is up at 100 Mbps, full duplex.
[ 1425.809143] tg3: eth0: Flow control is off for TX and off for RX.

root@D820:/# ifup eth0
Internet Systems Consortium DHCP Client V3.1.1
Copyright 2004-2008 Internet Systems Consortium.
All rights reserved.
For info, please visit http://www.isc.org/sw/dhcp/

wmaster0: unknown hardware address type 801
wmaster0: unknown hardware address type 801
Listening on LPF/eth0/00:15:c5:09:c5:5a
Sending on LPF/eth0/00:15:c5:09:c5:5a
Sending on Socket/fallback
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 7
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 20
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 15
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 9
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 10
No DHCPOFFERS received.
No working leases in persistent database - sleeping.

root@D820:~# dmesg
[ 1425.809137] tg3: eth0: Link is up at 100 Mbps, full duplex.
[ 1425.809143] tg3: eth0: Flow control is off for TX and off for RX.
[ 1507.628310] tg3 0000:09:00.0: irq 2297 for MSI/MSI-X
[ 1507.716767] ADDRCONF(NETDEV_UP): eth0: link is not ready
[ 1509.330294] tg3: eth0: Link is up at 100 Mbps, full duplex.
[ 1509.330301] tg3: eth0: Flow control is off for TX and off for RX.
[ 1509.330888] ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
[ 1520.212150] eth0: no IPv6 routers present


This is my try with static IP: modified /etc/network/interfaces


root@D820:~# vi /etc/network/interfaces
auto lo
iface lo inet loopback

#iface eth0 inet dhcp
#auto eth0

auto eth0
iface eth0 inet static
address 212.187.61.178
netmask 255.255.255.0
gateway 212.187.61.1

root@D820:/etc/network# ../init.d/networking restart
* Reconfiguring network interfaces...SIOCDELRT: No such process [ OK ]

retried it:
root@D820:/etc/network# ../init.d/networking restart
* Reconfiguring network interfaces... [ OK ]

root@D820:/etc/network# ifconfig
eth0 Link encap:Ethernet HWaddr 00:15:c5:09:c5:5a
inet addr:212.187.61.178 Bcast:212.187.61.255 Mask:255.255.255.0
inet6 addr: fe80::215:c5ff:fe09:c55a/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:81 errors:0 dropped:0 overruns:0 frame:0
TX packets:35 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:8616 (8.6 KB) TX bytes:4879 (4.8 KB)
Interrupt:18

root@D820:~# dmesg
[ 1932.000383] tg3 0000:09:00.0: irq 2297 for MSI/MSI-X
[ 1932.105029] ADDRCONF(NETDEV_UP): eth0: link is not ready
[ 1933.702326] tg3: eth0: Link is up at 100 Mbps, full duplex.
[ 1933.702343] tg3: eth0: Flow control is off for TX and off for RX.
[ 1933.702929] ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
[ 1943.912083] eth0: no IPv6 routers present


No internet connection, but I hope you guys understand this. ???

[kevinc]

@pdaalder What type of connection do you have. You mentioned 'plugging in the cable' so it's not wireless.
Of the various types of wired connections, which both nm and wicd are not good at detecting, there are those that use dhcp which is most easily detected, others require a proxy, others require a username and password, others require more information, such as DNS, sometimes primary and secondary, netmask, IP address.

If you have used this connection on another system, what information did you have to supply to be able to connect?

[Detonate]

Yes, we need to know if you are connecting through a router, or ar you connecting directly to a cable or dsl modem. One very simple reason for your problem could be a bad cable.

[pdaalder]

Not sure what you mean with type of connection, but I believe it is just a regular ethernet connection

My machine runs dual boot, so tried it with windows, but unfortunately I'm not have fun there even. Message: unable to contact your DHCP server.

The cable I use is connected normally to a windows xp machine. I compared the details of the LAN of machine A with machine B, and I adjusted the differences. No luck.

Is my card broken? I was using it last week fine (other location, so other connection, but wired also)

Do you think the provider is blocking it?

[Detonate]

Now we are on to something. It won't connect in windows either. Can you swap the cards in your two machines just to see what happens? And try another cable.

[pdaalder]

[Feeling stupid]
Damn, after all the time of research, unbelievable, it is the modem/router of the provider that was causing the problem. The problem was memory at the thingy. I called the provider, and explained what was happening, he told me that the router keeps a communication with a computer in memory. So my other computer was "unknown" and therefor it refused the connection. After rebooting (keeping energy of for 30sec) the router, the router did understood my machine, and now I'm happily typing this message of Kubuntu.

I'm in love with Kubuntu, amazing what has been accomplished, and thanks all for being that helpfull.
[/Feeling stupid]

[Detonate]

Glad you go ti working. We've all had those "Duh" moments.:)

[Fintan]

HI Detonate

I read your Howto because I have a problem here:
http://kubuntuforums.net/forums/index.php?topic=3104627.new#new

I did not follow your instructions because froebi has the exact same interface file set up as my default.

Maybe you could have a look and tell me where I am going wrong?

Thankx in advance

[marcopl]

shouldn't this faq be updated?

In Jaunty Jackalope, ( i have kubuntu 9.04), there is no resolv.conf but just /etc/resolvconf.

Pls advise.

[Detonate]

I am also running JJ and I have a resolv.conf file.

[marcopl]

I am also running JJ and I have a resolv.conf file.



that file was created only AFTER i got wicd working. before that i only had /etc/resolvconf

[Detonate]

Yes, the resolv.conf file is created by running DHCP. If using a static IP and DHCP has never been run, you would have to create the file. So in almost all cases, if DHCP has been successfully run there will be a resolv.conf file, but if it has never been run, then you would have to create the file to use a static IP. I will add a note to the howto.

BTW /etc/resolvconf is a directory and not a file.

[Detonate]

OK, marcopi, I added some info to the section about the resolv.conf file. Thanks for pointing that out.

[marcopl]

bro, many thanx for helping newbies out. ;D

[olderguy]

Can you (or someone else) please list the packages to remove in 9.04? Among those listed for 8.xx I see only network-manager, nothing with kde.

[Detonate]

Just remove the packages listed in the original post. That should do it. Remove network-manager, network-manager-kde.

[olderguy]

HowTo worked fine. Thanks very much. But FYI, there is no network-manager-kde in 9.04, at least on my system. And people should be warned that when they remove network-manager their networking component will (understandably) crash. Don't panic because KDE will restart within a few seconds, and you will not lose your terminal.

[marcopl]

Detonate, is it possible for u to expand this howto to include wireless interface as well?

[Detonate]

The problem with that is, I don't really have that much experience with wireless. I do use it on my laptop, and I have a couple of USB wireless devices lying around, but I really have not experimented with them enough to feel qualified on how to write a "howto". Actually, most wireless problems seem to be getting the device to work, and getting the the security set up. Both of which are somewhat beyond the scope of this howto. Most folks report that Wicd is the best way to go.

[marcopl]

The problem with that is, I don't really have that much experience with wireless. I do use it on my laptop, and I have a couple of USB wireless devices lying around, but I really have not experimented with them enough to feel qualified on how to write a "howto". Actually, most wireless problems seem to be getting the device to work, and getting the the security set up. Both of which are somewhat beyond the scope of this howto. Most folks report that Wicd is the best way to go.


understood bro. i have wicd running btw. was working all the while...until my laptop battery was drained and somehow the wireless interface - eth1 disappeared. now the wireless nic , bcm 4312 still shows up when i do 'hwinfo', except i dont know how to assign it as eth1?

[Ole Juul]

Thanks for the howto Detonate. I recently updated my partner's machine to 9.04 and so was back to DHCP which doesn't work well for my taste and local setup. No problem. I'm quite familiar with /etc/network/interfaces so I just went to fix it, but got a big surprise when I saw what it looks like now! Anyway, I found your excellent information, the key point of which (to me) was to "sudo apt-get remove network-manager". That's when the screen stopped responding and I had a really DUH moment. lol Using telnet to configure a remote machine's network connection has it's drawbacks. Suffice it to say that after sawing off the branch that I was sitting on, I had to leave my chair and actually go upstairs and sit at the relevant machine. ;D

[Detonate]

When I wrote the howto I did not consider that someone would be using it remotely. Glad you got it worked out.

[Ricey155]

bookmarked for use

needed this all day great post thanks should help a lot

[buckyjunior]

I seem to be having similar problems with getting (K)Ubuntu net-working on a circa 2003 IBM/Lenovo Netvista machine where I would like to be running Linux.

Except for deleting the KDE networking manager programs, I think I have followed most of the directions in this thread. The built-in network card works with (UGH!) Microsloth (on a separate HD) but not with Kubuntu 9.10 on another HD.

I get the temporary IP address in ifconfig with settings for DHCP. My router is set for DHCP and I get a listing for the Linux box (an IP address x.x.x.103) with a MAC address matching the built-in NIC (and another test with an _OLD_ additional NIC card).

Trying the static configurations still doesn't allow me to connect with my LAN/the internet.

I cannot ping my router as the false IP address I have cannot reach the router at 192.x.x.x.

I've been struggling with this for a couple of days now. I can't get anything out of this machine. If I were to try to get output, it would be transcribed from one machine's screen to another on my LAN. USB sticks don't seem to be recognized either (That's a different thread somewhere.)

I've enjoyed the versatility of (K)Ubuntu for a Linux environment, I just have had problems with machines that didn't like Linux. I hope that this scant outline might provide some point of departure for a solution to my problem.

Bucky
--It isn't easy being green.
Kermit

[Detonate]

Except for deleting the KDE networking manager programs, I think I have followed most of the directions in this thread.


If you don't do that, then the rest of the howto is not going to help. The whole premise of this is to get your network running without a network manager screwing things up.

[buckyjunior]

Thank you for the reply Detonate.

I've gone back and deleted the kde-network programs, rebooted, checked all the settings and I'm still not able to connect with my Kubuntu (8.04) Linux box through my router with DHCP. Other machines on my LAN are connected.

Perhaps my transcription of what I see will help solve my problem.

ifconfig shows two NICs connected with eth0 with a false IP address.

bucky@localhost:~$ ifconfig -a
eth0 Link encap:Ethernet HWaddr 00:09:6b:d5:aa:f6
inet6 addr: fe80::209:6bff:fed5:aaf6/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)

eth1 Link encap:Ethernet HWaddr 00:10:4b:6d:68:5f
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:122 errors:0 dropped:0 overruns:2 frame:0
TX packets:64 errors:11 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:37254 (36.3 KB) TX bytes:7199 (7.0 KB)
Interrupt:7 Base address:0x2040

eth0:avahi Link encap:Ethernet HWaddr 00:09:6b:d5:aa:f6
inet addr:169.254.10.213 Bcast:169.254.255.255 Mask:255.255.0.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1

eth1:avahi Link encap:Ethernet HWaddr 00:10:4b:6d:68:5f
inet addr:169.254.5.105 Bcast:169.254.255.255 Mask:255.255.0.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
Interrupt:7 Base address:0x2040

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 adddr: ::1/128 Scope:Host
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:61 errors:0 dropped:0 overruns:0 frame:0
TX packets:61 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:5228 (5.1 KB) TX bytes:5228 (5.1 KB)


Looking at the modified interfaces file, eth0 is set for DHCP as prescribed.

bucky@localhost:~$ cat /etc/network/interfaces
# network interfaces

# the loopback network interface
auto lo
iface lo inet loopback
address 127.0.0.1
netmask 255.0.0.0

# the primary network interface
auto eth0
iface eth0 inet dhcp

# the secondary network interface
# auto eth1
# iface eth1 inet dhcp


The resolv.conf file is set to external DHCP servers as well as the IP for my router--which is the same as in your example.


bucky@localhost:~$ cat /etc/resolv.conf
nameserver 192.168.0.1
nameserver 208.67.222.222
nameserver 208.67.220.220


My router is set to serve DHCP addresses and it seems to have located the Linux box's NICs and their MAC addresses.
http://home.comcast.net/~p.wehr/gfx/routerDHCP.jpg

Restarting the network doesn't seem to be able to locate the router's DHCP server. Bummer.


bucky@localhost:~$ sudo /etc/init.d/networking restart
sudo: unable to resolve host localhost
...
Listening on LPF/eth0/00:09:6b:d5:aa:f6
Sending on LPF/eth0/00:09:6b:d5:aa:f6
Sending on Socket/fallback
...
Listening on LPF/eth0/00:09:6b:d5:aa:f6
Sending on LPF/eth0/00:09:6b:d5:aa:f6
Sending on Socket/fallback
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 7
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 13
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 11
No DHCPOFFERS received.
No working leases in persistent database - sleeping.


And then obviously, my Linux box cannot ping the router or other machines on the LAN.


bucky@localhost:~$ ping -c3 192.168.0.1
PING 192.168.01. (192.168.0.1) 56(85( bytes of data.
From 169.254.5.105 icmp_seq=1 Destination Host Unreachable
From 169.254.5.105 icmp_seq=2 Destination Host Unreachable
From 169.254.5.105 icmp_seq=3 Destination Host Unreachable

--- 192.168.0.1 ping statistics ---
3 packets transmitted, 0 received, +3 errors, 100% packet loss, time 20076ms, pipe 3


As expected, other machines on the LAN and the router get 100% packet loss trying to find the Linux box.

Obviously, I've done something wrong or am missing some detail here.

Perhaps it's my karma. High overcast, mid 50s. I should be out planting my garden or up the Poudre fishing.

Thanks for helping to solve my network problem.
Bucky

"And don't tell me there isn't one bit of difference between null and space, because that's exactly how much difference there is. :-)" -- Larry Wall

[skunk]

What do you have in /etc/hosts

[buckyjunior]

Detonate.

the /etc/hosts file.


127.0.0.1 ibm/a0a5d118e94

# the following lines are desirable for IPv6 capable hosts
::1 ip6-localhost ip6-loopback
fe00::0 ip6-localnet
fe00::0 ip6-mcastprefix
fe02::1 ip6-allnodes
fe02::2 ip6-all-routers
fe02::3 ip6-allhosts
192.168.0.1 DI-524


Hmmm. I would speculate but I'm really in a foreign land here.

Bucky

[Detonate]

First, I would recommend disabling ipv6.

A search on this, or on the Ubuntu forum will tell you how to do this. I think that may be your problem.

[skunk]

bucky@localhost:~$ sudo /etc/init.d/networking restart
sudo: unable to resolve host localhost
...

Surely you need to have (at least) localhost defined in your /etc/hosts file

[buckyjunior]

Adding localhost to the /etc/hosts file, 127.0.0.1 seems to be now recognized as localhost.

As per http://kubuntuforums.net/forums/index.php?topic=3108234.0 followed by the link to disable ipv6 at http://www.webupd8.org/2009/05/how-to-disable-ipv6-in-ubuntu-jaunty.html, I set about to disable ipv6.

I get a response that the file
/proc/sys/net/ipv6/conf/all/disable_ipv6 does not exist.

Editing
/boot/grub/menu.lst and rebooting does not change anything. The file still doesn't exiist and I'm still not able to connect. I still get a self-generated IP address instead of the router suggested address.

I'm certainly at a loss.

Bucky
--
How can you have any pudding if you don't eat your meat?

[Detonate]

Try rebooting your router. Turn it off. Leave it off for a few minutes. Turn it back on. Then see if you get a dhcp offer from the router.

[buckyjunior]

Detonate,

Don't you ever sleep, or eat? You always seem to be here.

I rebooted the router which wiped out the references to the MAC addresses associated with the hardware on the Linux box.

A quick ping from the Linux box turned up nothing.
Restarting the network--again didn't receive any DHCPOFFERS from my router.

Is there something about
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval (number varies)
?

Isn't it supposed to be looking to my defined DHCP server/gateway? 192.168.0.1.
The $ff.ff.ff.ff seems like a mask to either nowhere or anywhere. This is getting deeper into unknown territory for me.

Do you think another distribution (not Debian based) might have some antique network routines that would better recognize my ~2002 vintage NIC card and router from probably the same era?

Or in your experience, are the possibilities narrowing toward a solution?

Bucky
Tools that follow standards NOT Standard tools - K.Prager

[buckyjunior]

For information only.

I've given up trying to get Linux to play nice with the NIC on the old IBM/Linovo desktop. My guess is that it may need proprietary drivers. Drivers that work are apparently included in the Windoze installation.

My (less than optimal) solution to meet my current needs is to run Virtual Box on the original XP disk and install Kubuntu on that. The NIC does all the things is it supposed to do through Virtual Box.

Thanks for trying folks.

Bucky

[Jabberwoc]

Also for information and to say a big THANKS to you, Detonate!

I didn't see any eth0 when I ran ifconfig but I did see lo.

I went ahead and followed your guide.

Happily I have a working wired connection again! I'm using 10.04, Lucid Lynx also.

I'm still puzzled as to how the connection got lost but I have your excellent fix to refer to now.

Many thanks from a UK Linux noob. ;D

[Detonate]

Happy to be of help. Great you got it working!!

[joneall]

If you want to watch the boot process you can edit the /boot/grub/menu.lst file and remove the words quiet and splash from the kernel line. Then when you boot up you will get to watch all the things that happen during boot, and if it hangs, you'll know where.

How do you do this with Grub2?

[Detonate]

Edit the /etc/default/grub file. Find the line that looks like this.

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

Remove the words quiet and splash and save the file.

Then run


sudo update-grub

[joneall]

Thanks, Floyd, for the great post!

[alefree]

Hi guys,
I read the topic, but I have a question? is this procedure still valid? ???
I have installed Kub10.04 (on a laptop HP Pavillion dv8000, Turion64...), and I have the problem that I cannot go in internet because the eth icon says "not managed" and when you clik on the icon it says "gestione reti disabilitata" (network gestion not enabled ?? On the fly translation..).
with the network manager I already set the wired connection (the Wifi too ... but for this I need to download the driver through the wired connection ... :'().

[Ole Juul]

Yes it is still valid. Generally it is better to set up your network without a GUI because that always works. :)

[Detonate]

Yes, the procedure is still valid. But before you attempt it read this thread.
http://kubuntuforums.net/forums/index.php?topic=3113181.msg238106#msg238106
and issue the following commands in a terminal.

sudo service network-manager stop
sudo rm /var/lib/NetworkManager/NetworkManager.state
sudo service network-manager start

If you wish to install a network manager follow the instructions in the above thread to install wicd.