How to set the static IP address on Ubuntu and pppoe when system boot

How to set the static IP address on Ubuntu:

$ sudo nano /etc/network/interfaces

then in nano editor add the following texts: 

# The loopback network interfaceauto loiface lo inet loopback
auto dsl-provideriface dsl-provider inet ppppre-up /bin/ip link set eth0 up # line maintained by pppoeconfprovider dsl-provider
auto eth0#iface eth0 inet manual# setting static ip...iface eth0 inet static        # ip address...        address 10.176.0.88        # network mask...        netmask 255.255.255.0        network 10.176.0.0        broadcast 10.176.0.255        # default gatway...        gatway 10.176.0.1

then ctrl+O & ctrl+x save and return to the command line:

restart the network:

$ sudo /etc/init.d/networking restart

if you need start pppoe when system booted, using the commands :

Press Ctrl+Alt+T or go to Applications -> Accessories -> Terminal. Run:

in terminal:

$ sudo pppoeconf

Set the username and password.

Now to connect, run this pon command in the terminal:

$ sudo pon dsl-provider

To disconnect:

$ sudo poff

We really want it to connect automatically though, so edit /etc/rc.local by running:

$ sudo nano /etc/rc.local

That opens the file in a text editor. Before the line that says exit 0, add these lines:

# For PPP auto-connect.killall pppdifconfig eth0 uppon dsl-provider