I can't connect to internet, there is no internet, network on Ubuntu 12.04
 

Hi.

Can You help me? I wanted to try new Ubuntu. I installed it without problem but as soon as i rebooted after installation i found problem with my internet connections. There is no network. I have 2 lan cards, in ifconfig thery are present, ubuntu sees them in taskbar (near clock there is network/internet icon) but i can't connect to internet, maybe it is my fault but on 11.10 these cards work fine. As soon as i log into Ubuntu i see "connection lost" or "wired network not connected" (or something like that, i forgot the exact word for it).

ifconfig

lsmod:



lshw:

Can You tell me what to do in order to set up connections, having internet?

They're simply not configured.
Dunno if and which network manager you're using, but issuing a simple
on the X device which is connected to a DHCP server should get you up and running, provided Ubuntu includes dhcpcd :)
Anyway, look first inside your network manager settings.

Are you sure? Can me tell exacly which line listed above shows that it is not configured?

Network from Ubuntu.
I did. I set up my internet manually and there wasn't any network connection at all while on 11.10 automatically shows up after boot and log in. I don't thing that i configured it, in mentwork menager i just see: auto - see my attached file.

As You can see, on 11.10 it is auto settings. I provided also my internet connection information. Driver: sundance works.

I said that your network interfaces are not configured because the ifconfig output reports that both eth0 and eth1 don't have an IP address

I see. Inside the Ubuntu 12.04 documentation it is said that wired interfaces should automatically connect as soon as an ethernet cable is plugged in. Are you sure that your cable works correctly? Can you try with another one before proceeding?

Thanks.

I'm sure that cable is ok because on the same cable, on the same computer with the same lan cards but on a different hard disk sits Ubuntu 11.10 and when i switch to 11.10 wired connection is right away avilable when i log in into Ubuntu.

Could this be the situation under your network manager in 12.04?

Yeah, that's looks about right. I'm running Lubuntu 12.04 (Ubuntu with Lxde instead of Unity, same thing). That's usually what happens when more than one ethernet card is detected. Just click the Add button and pick which card you want to connect with. Then set it to DHCP (I think it's called 'Automatic'?), and it will connect.

No, it is not this problem. Check post number 3. I have two wired connection recognized in network menager but i can't connect to internet.

I checked two things:

-run from live instllation disk: also couldn't connect to internet, as soon as i booted i see "network disable"
-I CAN'T EVEN LOG TO MY ROUTER, i add ip addres in addres bar of firefox and i see that i can't connect because there is no connection!

I just don't know what to do. I tried with

and i had this:

(sudo: dhcpcd: didn't find command - translated to english ;) )

I attached files contains:

-sudo dhcpcd ethX
-my two wired connections in network menager (as you can see there are 3 connections right now cause it is from 11.10 and works, on 12.04 are only Wired Connection 1 and Wired Connection 2 but doesen't work at all)

But despite it i have this info:

http://img220.imageshack.us/img220/6...sconnected.png

Uploaded with ImageShack.us

Here is a link

http://img220.imageshack.us/img220/6...sconnected.png

(network disconnected)

Of course you can't. None of your ethX interfaces have an IP address, so they cannot connect to your router administration web page.
Sorry for that. You should try with dhclient instead of dhcpcd, as it should already be installed on an Ubuntu system.

I already looked at the similar screenshots you previously posted, but I can't see nothing really useful in them, sorry. Perhaps you should look under the IPv4 tabs of your network interfaces to see if DHCP is selected or not.
Don't know if one of your ethX interfaces is a wireless one, but this screen only shows me that it isn't connected to any network...

That is something i don't understand - on 11.10 it was right after installation.

I tried to do this on 11.10 to find what it is and i have:

Could you help me to set up this with dhclient? I haven't done it yet.


Yes. It is wired and i have checked DHCP.

I've checked few things again.


11.10: /etc/network/interfaces
12.04: /etc/network/interfaces
the same


11.10: /etc/NetworkManager/NetworkManager.conf
12.04: /etc/NetworkManager/NetworkManager.conf

there is only one different thing here - dns=dsnmasq. I've uncommented this but nothing has changed. I've changed from "managed=false" to "managed=true" and restarted it with command sudo service network-manager restart, it was restarted but still no internet connection.

Some settings from system settings:

-wired connections:

http://imageshack.us/f/265/cablenotplugged.png/

as You can see, "cable is not plugged"...geeez.

It not as in link with topic above with "not managed" like here:

http://img824.imageshack.us/img824/8001/f5fpl.png

As you can see, it is different than mine. I have connections but "cable is not plugged".

Now, my settings of wired connections and ip4 settings in wired connections:

http://img834.imageshack.us/img834/5...ectionsip4.png

As you can see in first window at the top of this screen, near wired connection is when it was last used: "nigdy" means never in english!


I really don't know what i can do more.

On 11.10 you have the network automatically configured on start (i.e. your interfaces get an IP address automatically) so you can access your router and everything beyond it (internet). On 12.04 you still have to configure your interfaces first, then you can get to the router and beyond it.


Why do you keep trying on 11.10 where everything already works?
You should try with dhclient on 12.04! ;)
Try commenting out (i.e. put a # at the start of the line) the no-auto-default=XXXX line in /etc/NetworkManager/NetworkManager.conf in Ubuntu 12.04 and restart NetworkManager:
Maybe it's that option that's preventing NetworkManager from working as you'd expect.
The "cable not plugged" message still bothers me, though...

Good to know. Thanks. I didn't know this.


To show only differences ;)

This is a problem. I don't know how to configure dhclient using terminal in 12.04 cause i haven';t done it yet, don't know how to cinfigure - i've serched over the web but haven't found yet answer.

I will check it.
Yes, that's weird.

You shouldn't configure a thing. Simply run it with no arguments to send a DHCP request for every network interface or specify the network interface you want configured.

Heh, i did it like this:

sudo dhclient eth0 - terminal was working but login prompt was busy, nothing happened
sudo dhclient eth1 - terminal accepted command, i could enter new commands but didn't change anything after sudo services network-manager restart - still no wired connections.

Maybe kernel is at fault or driver? I don't know how to change this kind of drivers. I would check which driver i have on 11.10 and which is on 12.04 but i don't know how to do it.