Please keep in mind that the new Sarge installer is a beta, and as such you should investigate and report problems.
Open up the network interface configuration file - /etc/network/interfaces. In that file you should have a section for eth0, the first Ethernet interface. It will also have a section for the loopback "lo" device (this must be present for the system to work so don't remove it).
Here is my interfaces file for reference. This file should work for most setups:
# /etc/network/interfaces -- configuration file for ifup(8), ifdown(8)
# The loopback interface
iface lo inet loopback
# The first network card - this entry was created during the Debian installation
iface eth0 inet dhcp
Make sure the driver module for your network card is loaded and then restart networking. If the driver is not loaded, use modprobe
to load it and make sure the driver is mentioned in /etc/modules so it will be automatically loaded on boot.
Restart networking: /etc/init.d/networking restart
If all is set up correctly you will see the DHCP client asking for an address lease and get one (this may take a while depending on your network).