  IP Geolocation is a key enabler for many areas of application like Content
Delivery Networks, targeted advertisement and law enforcement. Therefore, an
increased accuracy is needed to improve service quality. Although IP
Geolocation is an ongoing field of research for over one decade, it is still a
challenging task, whereas good results are only achieved by the use of active
latency measurements. This paper presents an novel approach to find optimized
Landmarks positions which are used for active probing and introduce an improved
location estimation. Since a reasonable Landmark selection is important for a
highly accurate localization service, the goal is to find Landmarks close to
the target with respect to the infrastructure and hop count. Current techniques
provide less information about solving this problem as well as are using
imprecise models. We demonstrate the usability of our approach in a real-world
environment. The combination of an optimized Landmark selection and advanced
modulation results in an improved accuracy of IP Geolocation.
