Setting up an USB network will allow us to speed up the installation by providing a faster, as well as an easier way to transfer files than the serial method used up to now.
There are two steps involved in setting up the network:
Establish the iPAQ connection to the LAN (Local Area Network), if it exists. Anyway, if it does not exist, this connection will be used to access the Internet. We will use the mechanism known as proxy_arp, that will assign two IP addresses to the host, one for itself and one for the iPAQ.
Establish the iPAQ connection to the Internet. If the GNU/Linux host is part of a LAN and already has access to it, then no further work is required, and the iPAQ should be able to access it too. However, if the host is directly connected to the Internet through a modem, then we will have to set a mechanism called NAT (Network Address Translation), in order to map iPAQ's address to the same IP address the GNU/Linux host uses to access the Internet. This is required, as your ISP (Internet Service Provider) probably supplied only a single address to you. Another consideration will be to declare the iPAQ to the firewall, so it gets proper authorizations to access the Internet.