ip address / network configuration

[Carlos S]

Hi

I have a Ubuntu 10.10 desktop edition installed with DHCP for
IP/network configuration. How do I assign a static IP addresses to a
network interfaces? Also, How can one configure multi-homed network in
Ubuntu?

A quick google search led me to following examples, where replacement
of existing DHCP line is told.
http://www.ubuntugeek.com/change-ubuntu-system-from-dhcp-to-a-static-ip-address.html
http://www.howtogeek.com/howto/ubuntu/change-ubuntu-server-from-dhcp-to-a-static-ip-address/

Interestingly I don't have any such DHCP config line in my system's
'/etc/network/interfaces'. Following is what I have:
{{
auto lo
iface lo inet loopback
}}}

So where is my existing IP address config?

Also, if I edit network config in GUI then it is not written in
interfaces file, although the config seems to be applied. Any
elaboration on this network config would be really helpful.

I have done this on CentOS and typically it is done in
/etc/syconfig/networking-scripts/ifcfg-eth0 (and
/etc/syconfig/networking-scripts/ifcfg-eth0:1 for multi-homed
networking). I will really appreciate if someone could explain this or
point me to a good documentation link related to Ubuntu.

-
cs.