11 research outputs found
Compact routing for the future internet
The Internet relies on its inter-domain routing system to allow data
transfer between any two endpoints regardless of where they are
located. This routing system currently uses a shortest path routing algorithm
(modified by local policy constraints) called the Border Gateway
Protocol. The massive growth of the Internet has led to large routing
tables that will continue to grow. This will present a serious
engineering challenge for router designers in the long-term,
rendering state (routing table) growth at this pace unsustainable.
There are various short-term engineering solutions that may slow the
growth of the inter-domain routing tables, at the expense of increasing
the complexity of the network. In addition, some of these require manual configuration, or
introduce additional points of failure within the network. These solutions may
give an incremental, constant factor, improvement. However,
we know from previous work that all shortest path routing algorithms
require forwarding state that grows linearly with the size of the
network in the worst case.
Rather than attempt to sustain inter-domain routing through a
shortest path routing algorithm, compact routing algorithms exist that
guarantee worst-case sub-linear state requirements at all nodes by
allowing an upper-bound on path length relative to the theoretical
shortest path, known as path stretch. Previous work has shown
the promise of these algorithms when applied to synthetic graphs
with similar properties to the known Internet
graph, but they haven't been studied in-depth on Internet topologies
derived from real data.
In this dissertation, I demonstrate the consistently strong
performance of these compact routing algorithms for inter-domain routing by performing
a longitudinal study of two compact routing algorithms on the Internet
Autonomous System (AS) graph over time.
I then show, using the k-cores graph decomposition algorithm, that
the structurally important nodes in the AS graph are highly stable
over time. This property makes these nodes suitable for use as the
"landmark" nodes used by the most stable of the compact routing
algorithms evaluated, and the use of these nodes shows similar strong
routing performance.
Finally, I present a decentralised compact routing algorithm for
dynamic graphs, and present state requirements and message overheads
on AS graphs using realistic simulation inputs.
To allow the continued long-term growth of Internet routing state, an
alternative routing architecture may be required. The use of the
compact routing algorithms presented in this dissertation offer
promise for a scalable future Internet routing system
Multilevel MDA-Lite Paris Traceroute
Since its introduction in 2006-2007, Paris Traceroute and its Multipath
Detection Algorithm (MDA) have been used to conduct well over a billion IP
level multipath route traces from platforms such as M-Lab. Unfortunately, the
MDA requires a large number of packets in order to trace an entire topology of
load balanced paths between a source and a destination, which makes it
undesirable for platforms that otherwise deploy Paris Traceroute, such as RIPE
Atlas. In this paper we present a major update to the Paris Traceroute tool.
Our contributions are: (1) MDA-Lite, an alternative to the MDA that
significantly cuts overhead while maintaining a low failure probability; (2)
Fakeroute, a simulator that enables validation of a multipath route tracing
tool's adherence to its claimed failure probability bounds; (3) multilevel
multipath route tracing, with, for the first time, a Traceroute tool that
provides a router-level view of multipath routes; and (4) surveys at both the
IP and router levels of multipath routing in the Internet, showing, among other
things, that load balancing topologies have increased in size well beyond what
has been previously reported as recently as 2016. The data and the software
underlying these results are publicly available.Comment: Preprint. To appear in Proc. ACM Internet Measurement Conference 201
Characterizing User-to-User Connectivity with RIPE Atlas
Characterizing the interconnectivity of networks at a country level is an
interesting but non-trivial task. The IXP Country Jedi is an existing prototype
that uses RIPE Atlas probes in order to explore interconnectivity at a country
level, taking into account all Autonomous Systems (AS) where RIPE Atlas probes
are deployed. In this work, we build upon this basis and specifically focus on
"eyeball" networks, i.e. the user-facing networks with the largest user
populations in any given country, and explore to what extent we can provide
insights on their interconnectivity. In particular, with a focused user-to-user
(and/or user-to-content) version of the IXP Country Jedi we work towards
meaningful statistics and comparisons between countries/economies. This is
something that a general-purpose probe-to-probe version is not able to capture.
We present our preliminary work on the estimation of RIPE Atlas coverage in
eyeball networks, as well as an approach to measure and visualize user
interconnectivity with our Eyeball Jedi tool.Comment: In Proceedings of the Applied Networking Research Workshop (ANRW '17
A Long Way to the Top: Significance, Structure, and Stability of Internet Top Lists
A broad range of research areas including Internet measurement, privacy, and
network security rely on lists of target domains to be analysed; researchers
make use of target lists for reasons of necessity or efficiency. The popular
Alexa list of one million domains is a widely used example. Despite their
prevalence in research papers, the soundness of top lists has seldom been
questioned by the community: little is known about the lists' creation,
representativity, potential biases, stability, or overlap between lists.
In this study we survey the extent, nature, and evolution of top lists used
by research communities. We assess the structure and stability of these lists,
and show that rank manipulation is possible for some lists. We also reproduce
the results of several scientific studies to assess the impact of using a top
list at all, which list specifically, and the date of list creation. We find
that (i) top lists generally overestimate results compared to the general
population by a significant margin, often even an order of magnitude, and (ii)
some top lists have surprising change characteristics, causing high day-to-day
fluctuation and leading to result instability. We conclude our paper with
specific recommendations on the use of top lists, and how to interpret results
based on top lists with caution.Comment: To be published at ACM IMC 2018. Web site with live data under:
https://toplists.github.i
Clusters in the expanse: Understanding and unbiasing IPv6 Hitlists
Network measurements are an important tool in understanding the Internet. Due to the expanse of the IPv6 address space, exhaustive scans as in IPv4 are not possible for IPv6. In recent years, several studies have proposed the use of target lists of IPv6 addresses, called IPv6 hitlists. In this paper, we show that addresses in IPv6 hitlists are heavily clustered. We present novel techniques that allow IPv6 hitlists to be pushed from quantity to quality. We perform a longitudinal active measurement study over 6 months, targeting more than 50 M addresses. We develop a rigorous method to detect aliased prefixes, which identifies 1.5 % of our prefixes as aliased, pertaining to about half of our target addresses. Using entropy clustering, we group the entire hitlist into just 6 distinct addressing schemes. Furthermore, we perform client measurements by leveraging crowdsourcing. To encourage reproducibility in network measurement research and to serve as a starting point for future IPv6 studies, we publish source code, analysis tools, and data