[SOLVED] Network connection configuration Ubuntu 10.04

taylorkh · 07-23-2010, 02:57 PM

I guess this should come under the title "why can't they leave well enough alone?" Today I had occasion to configure a couple of machines with static IP addresses for some testing. My 8.04 machine - no problem. Invoke network-admin, unlock (with sudo credentials), set the desired IP, netmask and gateway. It is good to go.

On the 10.04 box I did the following:

Right clicked on the network icon in the notification area (nm-connection-editor) - I see Auto eth0 (last used, never). So what have I been using for connectivity since I installed 10.04???

I then select Auto eth0 and press [Edit]. Under the IPv4 Settings tab I change "Method" Manual and enter my settings. However, I cannot Apply the changes - the [Apply] button is grayed out.

So I try the same thing via the menu System; Preferences; Network Connections - same problem the [Apply] button is grayed out.

So then I create a desktop icon to "gksu nm-connection-editor". Now I can Apply my changes and perform my testing. Then it is time to set things back to DHCP. Should be simple.

I invoke "gksu nm-connection-editor" from my icon. Change Auto eth0 back to Method: Automatic (DHCP). Apply and the network icon appears to restart. But I have no Internet connectivity.

I can reach my router. I can reach my DSL modem. The connection to the Internet is still working on other PCs. In frustration I reboot the 10.04 box. I still cannot access the Internet. And the Auto eth0 interface shows never used.

I change Method: to Automatic (DHCP) Addresses only and enter my DNS servers for Opendns.org. Reboot and I am now able to connect to the Internet. Remove the DNS addresses and no connection. I did NOT have these specified in the network connection setup before changing to/from a static IP address.

While doing all this it seems that a new network connection "Wired network1" was created although it shows never used. I delete it, no change. I delete Auto eth0 and reboot.

Now another new network connection "Auto Ethernet" appears and I can connect to the Internet without having the specify the DNS addresses in the network connections configuration. Interestingly this connection shows Last Used - now! Also after removing Auto eth0 and trying to Apply changes I am prompted for my password when I click the [Apply] button (starting the applet from the notifier icon, not my gksu launcher).

What more can I say?

Ken

tredegar · 07-24-2010, 03:52 AM

Network-Mangler is buggy. I could not set a static IP with NM either.

A better solution for managing wireless connections is to install wicd, which will do what you want.

scheidel21 · 07-24-2010, 06:34 PM

WICD works well, but you can also edit the interfaces file /etc/network/interfaces get a root terminal then use nano to edit the interfaces file. It should look something like this.

Code:

allow-hotplug eth0
iface eth0 inet static
   address xxx.xxx.xxx.xxx
   netmask 255.255.255.0
   network xxx.xxx.xxx.0
   broadcast xxx.xxx.xxx.255
   gateway xxx.xxx.xxx.xxx

Save the file then run

Code:

/etc/init.d/networking restart

hope this helps

taylorkh · 07-24-2010, 06:51 PM

Thanks scheidel21,

That does not seem to be the case in Ubuntu 10.04.

Quote:

ken@taylor12:~$ cat /etc/network/interfaces
auto lo
iface lo inet loopback

My working interface, Auto Ethernet, is not in the file. Nor was Auto eth0 which I deleted with the gui tool.

Ken

tredegar · 07-25-2010, 04:27 AM

Quote:

My working interface, Auto Ethernet, is not in the file.

You have to put it there. See scheidel21's post.

Or just install and use wicd

taylorkh · 07-26-2010, 08:46 AM

OK, I added it thusly:

Quote:

allow-hotplug eht0
iface eth00 inet static
address 192.168.0.140
netmask 255.255.255.0
network 192.168.0.0
broadcast 192.168.0.255
gateway 192.168.0.1

and ran the restart:

Quote:

ken@taylor12:~$ sudo /etc/init.d/networking restart
* Reconfiguring network interfaces... Ignoring unknown interface eth0=eth0.

It does not appear that Ubuntu 10.04 follows the normal network configuration conventions.

I may give wicd a try. However, since I deleted Auto eht0 and allowed Ubuntu to create Auto Ethernet I can stop, start and change the network settings using connection editor.

Ken

sem007 · 07-26-2010, 09:46 AM

There is a mistake in your previous quote. I assume you did correct it.

Quote:

iface eth0 inet static

first stop your network-manager service if it is running.

Code:

/etc/inin.d/network-manager stop

set IP address in interface file and then restart network service.

One more thing, if still you have problem change interface name eth0 to eth1.( i had faced interface name problem previously )

tredegar · 07-26-2010, 12:37 PM

You should check what your interfaces are called with sudo ifconfig
Do not make any changes to the local interface

Quote:

ken@taylor12:~$ sudo /etc/init.d/networking restart
* Reconfiguring network interfaces... Ignoring unknown interface eth0=eth0.

My guess is that NM is running.

Network-Mangler should not be running if you prefer to use the interfaces file method. In my experience NM currently causes more problems than it solves, except for managing "USB mobile phone dongles", which it does well.

Please confirm that your router is at 192.168.0.1

I can confirm that 10.04 honours a properly constructed interfaces file. Spelling mistakes will not be tolerated though.

taylorkh · 07-26-2010, 01:58 PM

Yes the 00 was my typoo. Considering that network manager is working with the new Auto Ethernet I am leaving well enough alone for the time being on my machine. I did uninstall network manager and install wicd on a Ubuntu 10.04 virtual machine. Works great. I will consider it my fallback for the next time network manager gets hosed again.

Thanks again all,

Ken