Ubuntu Network manager, static interface setup, multiple profiles, no internet, no dns

Recently I decided to experiment with the multiple profiles feature of the network manager provide by Ubuntu 8.04. I set up my lan network card with a static ip address so that I could manager port forwarding on my router specifically for my laptop.

I still wanted to be able to switch to the roaming mode provided by the network manager if I went to university or some where else. So I decide to save the set up in the network manager as a separate profile. I then saved other profile for the roaming modes on my wireless lan, and my cable lan interfaces.

After a restart I found that I could no longer get out on the internet after start up. I was not sure what the problem was. I could ping my router but nothing beyond my router. In checking my network manager set up I could see that where I used to have my router as a dns, I now had nothing.

So I add some dns servers saved the settings under my static profile and applied these setting buy clicking the green tick. Now every thing was working again. I could connect to the internet web pages would now load in firefox.

Again after a restart I found I had the same problem so I check my network manger and found that the settings were still there but were not applied. So I again choose the correct profile and applied the settings. This behaviour of being not being set up after a restart continued. It gets a little irritating having to go into network manager and apply setting after ever restart.

After reading around in fourums I found about about resov.conf resolvconf /etc/resolv.conf, /etc/resolvconf/interface-order and /etc/resolvconf/resolv.conf.d/. I could see that in interface-order and ifconfig my cabled lan card was begin configured correctly at start. In the resolv.conf file no dns servers were configured at start up, having no dns server to resolve requests out to the internet I could not browse the web or send emails or any thing you would need to do.

To solve the problem of not being set up at start up open the /etc/resolveconf/resolv.conf.d/base as root in a text editor and add a dns server like your router or some other dns server. Read the man resolvconf to find out why. Redundancy here is a good thing, have it point to more then one dns server.

Simply place entries like "nameserver 127.0.0.1" or "nameserver #your router#". Obviously 127.0.0.1 is localhost and probably wont work for the average set up. If your not sure what dns servers to use, ping a top level domain like www.com or www.co.za and get their ip address. Do a traceroute and look for domain names with .dns in them. You can see and example of how network manager saves one of these file in /etc/resolvconf/resolv.conf.d/original.

linux the cisco vpn and monash south africa

I have spent quite a bit of time trying different options for the vpn connection to Monash South Africa. The open source vpnc dose not work because when importing the cisco profile it warns that IP tunnelling across TCP has been enabled. Which may cause undesired resualts, in this case it simply dose not work.

The only option left for linux is the cisco client which has not been updated since 2006. Major problem. Thus we now have to go to projects.tuxx-home.at. Here is the only way to get support for the cisco linux vpn client. There are instructions for intallation, patching and support forums. Every thing a person would need. I have used them on a number of different kernel builds, 2.6.18 -- 2.6.24. They all worked.

The vpn client on the web site dose not, but you still need to down load it to get the correct profile configuration file. It is called sa.pcf. You will need to copy that file to the cisco /etc/opt/cisco-vpnclient/Profiles/. Then all you need to do to start it is type "sudo vpnclient connect sa".
Enter your user name and password and every thing should work.

I have found some small issues with the gnome network manager and haveing both my lan network card and wireless network card enabled. So depending on how I am connecting to the internet I disable which ever one I am not using. Type "ifconfig" to find out which device to disable. Then type "ifcofig eth#" where # is the device number, some thing like 0 or 1.

Here is some more info on getting the cisco vpn working www.blog.arun-prabha.com/2008/05/01/cisco-vpn-installation-issue-with-ubuntu-804-hardy-heron/.

Problems in Ubuntu 8.04 LTS

I recently upgraded to Ubuntu 8.04 LTS. I found that after using it for about 20 minuites their were certain things I could do that would totally crash the whole system. Later I found that it was a bug in the released kernel, check https://bugs.launchpad.net/ubuntu/+source/linux/+bug/188226.

It has to do with the cpu schedualer (Completely Fair Schedualer), not being configured properly for the desktop system. Their is already a way to fix it, but in requires over 100 mb of downloads to fix the problem. This will be a serrious problem to people who pay exhorbitant rates for internet access.

The basic solution is to update your system to an the latest development release kernel. From 2.6.24-16-generic t0 2.6.24-17-generic. Caution this 2.6.24-17-generic kernel
is a developmental release used for testing changes and bug fixes, it is not the same as the release version kernel. This new kernel will only be released 2008-07-01 it the next version of hardy, ubuntu-8.04.1.

Any way I upgraded to ensure that I have a Linux desktop that dose not stall any time I open two many windows or try to do thing as a different users, ie every time i use the sudo command to do some thing cpu intensive.

Fix
Using synaptic
Open Synaptic > Settings > Repositories
Go to the updates tab and select Pre-released updates ( hardy proposed)
Close the window and reload the package information.
Either navigate through the Base System Section or search to find
linux-image-2.6.24-17-generic
linux-ubuntu-modules-2.6.24-17-generic
Select both packages.
If you are using an nvidia graphics card you will need to also up grade it. Serach for
nvidia-glx-new - we want the version that matches our kernel, 169.12+2.6.24.12-17.36 instead of the old one 169.12+2.6.24.12-16.36 notice that the 12-16 / 12- 17 referes to the version of kernel supported. This should automatically include the
linux-restricted-modules-2.6.24-17-generic. Which include the binary / compiled modules necessary for the nvidia driver to work.
This should be all the updates that you need to fix the problem with out a major difficulty.
Next click apply and wait.
When it finished be sure to disable the Pre-released updates ( hardy proposed)
Synaptic > Settings > Repositories
Go to the updates Tab and select Pre-released updates ( hardy proposed)
And reload the package lists.

That should fix the problem, all this is described in the bug report check https://bugs.launchpad.net/ubuntu/+source/linux/+bug/188226. It also includes instructions on how to compile the kernel form source with the correct options. For more advanced users. This would probable save people form having to download a whole new kernel, and graphics card drivers.

vlc segmentation fault

I recently had problems with vlc media player. It would crash unexpectedly when running. It would not start when run from the Applications > Sound & Video > VLC. Occasionally it would start up but it would look terrible, or start two player interfaces. I then turned to the console using vlc, or wxvlc to get it to run. Some times it would come out with two player interface's, and whole string of exceptions.

Solution

in your home directory /home/yourhome/ their is a config directory for vlc called .vlc /home/yourhome/.vlc go and delete it completely. VLC automatically creates it when it is frist started. This will reset all the settings that could cause this type of problem.
rm /home/[you home dir]/.vlc

Immediately after doing that I tryied vlc from the application menu and it worked. I expect that I am not the only one to have this problem. I hope it helps some one else out there.