As you enter this step, if the system detects that you have more than one network device, you'll be asked to choose which device will be your primary network interface, i.e. the one which you want to use for installation. The other interfaces won't be configured at this time. You may configure additional interfaces after installation is complete; see the interfaces 5 man page. By default, &d-i; tries to configure your computer's network automatically via DHCP. If the DHCP probe succeeds, you are done. If the probe fails, it may be caused by many factors ranging from unplugged network cable, to a misconfigured DHCP setup. Or maybe you don't have a DHCP server in your local network at all. For further explanation check the error messages on the third console. In any case, you will be asked if you want to retry, or if you want to perform manual setup. DHCP servers are sometimes really slow in their responses, so if you are sure everything is in place, try again. The manual network setup in turn asks you a number of questions about your network, notably IP address, Netmask, Gateway, Name server addresses, and a Hostname. Moreover, if you have a wireless network interface, you will be asked to provide your Wireless ESSID and a WEP key. Fill in the answers from . Some technical details you might, or might not, find handy: the program assumes the network IP address is the bitwise-AND of your system's IP address and your netmask. It will guess the broadcast address is the bitwise OR of your system's IP address with the bitwise negation of the netmask. It will also guess your gateway. If you can't find any of these answers, use the system's guesses — you can change them once the system has been installed, if necessary, by editing /etc/network/interfaces.