Solutions for mobile ad hoc routing have matured over the last decade. Building atop these foundations, new challenges are set for MANETs, such as integration in the Internet core. On this topic, this paper designs and evaluates MPR-OSPF, an extension of the OSPF protocol enabling its operation on networks that may include both MANET nodes and usual fixed routers. Automatic integration of different types of vehicular ad hoc networks (VANETs) in the IP infrastructure is then possible using the classic OSPF framework. Techniques used therefore are derived from OLSR, the MANET routing protocol that is the most compatible with traditional IP environments.