My friend Jason use ADSL and his Ubuntu9.10 machine can not connect to internet with the default network-manager come with Ubuntu 9.10.Everytime the machine startup,he need to type pppoeconf command and configure to access to internet.Here is how to fix this problem in Ubuntu 9.10.

Step1:Update Network Manager to the latest version from PPA

Open up terminal from Applications->Accessories->Terminal to type following command to add the key first:

sudo apt-key adv --keyserver --recv-keys BC8EBFE8

Edit /etc/apt/sources.list by this command:

sudo gedit /etc/apt/sources.list

append following to end of the file and save it.

deb  karmic main
deb-src karmic main

Now,type this two command to update the network-manager:

sudo aptitude update
sudo aptitude safe-upgrade

Step2:configuration to fix the conflict between pppoe and network-manager

Edit /etc/NetworkManager/nm-system-settings.conf

sudo gedit /etc/NetworkManager/nm-system-settings.conf

find and change “managed=true” (without quotes).

Edit /etc/network/interfaces,

sudo gedit /etc/network/interfaces

change its content to:

auto lo
iface lo inet loopback

Delete /etc/resolv.conf by this command:

sudo rm -rf /etc/resolv.conf

Now,restart machine or restart the network-manager by this command:

sudo /etc/init.d/network-manager restart

Step3:Add DSL connection to network-manager and make it auto-connect at login.

Right click on network-manager icon and select “edit connections”

Delete useless connection.In DSL tab,click Add and then input your Username and Password.

Remember check the “Available to all users” (marked in picture) to prevent  keyring locked problem.