The European project GeoNet aims at specifying and implementing a geographic addressing and routing protocol with support for IPv6 to be used to deliver messages between cars but also between cars and the roadside infrastructure within a designated destination area. This goal is not only technological even though this work will be used in other projects like SafeSpot, CVIS and COOPERS or by the CAR 2 CAR Communication Consortium, but also raises scientific challenges: until now, most of the communication were though as communication between two points (1-to-1), while lots of ITS applications rather require 1-to-n or even n-to-n networking capabilities. The goal of this paper is to give the reader an overview of the needs, of the challenges - scientific and technological - and of the development of GeoNet as well as its expected impact