Master thesis : Analysis of IPv6 Extension Header Processing/Transmission over the wide Internet

Abstract

Intended to solve the various issues related to IPv4, IPv6 also introduced a new mechanism, improving support of extensions or options within the IP protocol. By chaining one or multiple additional headers, called extension headers, inside an IPv6 packet, this mechanism allows a source to provide supplementary information to the network or a destination without modifying the shape of the main IPv6 header. Despite their practicality, several measurements have shown some difficulties for the latter to reliably traverse the Internet, due to the various filtering policies applied by different autonomous systems. To improve their survivability and produce a more complete formalisation on how to manage these extension headers, it is therefore essential to have access to recent measurements. The most recent one dating from June 2015, this master thesis aims at providing a more current but also more complete measure than the one previously performed. To this end, a new probing methodology has been developed, in addition to greatly extending the tested extensions headers set. Using these new methods, two sets of measurements, one between collaborative nodes and the other towards non-collaborative one, were performed to produce measurements as accurate and reliable as possible. Both techniques confirmed the current instability of the IPv6 extension header mechanism, but also the transmission difficulties encountered by certain types of header. Finally, this study also aimed at identifying the autonomous systems responsible for these drops, to outline the criticality of the problem and possibly localise it within the network. The obtained results highlighted the severity of the problem and expose the fact that drops can be caused by any type of autonomous system, present on the packet's routing path.