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congratulations to Guillermo Baltra for his PhD

I would like to congratulate Dr. Guillermo Baltra for defending his PhD at the University of Southern California in August 2023 and completing his doctoral dissertation “Improving network reliability using a formal definition of the Internet core”.

Guillermo Baltra (right) and his thesis advisor.

From the abstract:

After 50 years, the Internet is still defined as “a collection of interconnected networks”. Yet seamless, universal connectivity is challenged in several ways. Political pressure threatens fragmentation due to de-peering; architectural changes such as carrier-grade NAT, the cloud makes connectivity indirect; firewalls impede connectivity; and operational problems and commercial disputes all challenge the idea of a single set of “interconnected networks”. We propose that a new, conceptual definition of the Internet core helps disambiguate questions in analysis of network reliability and address space usage.


We prove this statement through three studies. First, we improve coverage of outage detection by dealing with sparse sections of the Internet, increasing from a nominal 67% responsive /24 blocks coverage to 96% of the responsive Internet. Second, we provide a new definition of the Internet core, and use it to resolve partial reachability ambiguities. We show that the Internet today has peninsulas of persistent, partial connectivity, and that some outages cause islands where the Internet at the site is up, but partitioned from the main Internet. Finally, we use our definition to identify ISP trends, with applications to policy and improving outage detection accuracy. We show how these studies together thoroughly prove our thesis statement. We provide a new conceptual definition of “the Internet core” in our second study about partial reachability. We use our definition in our first and second studies to disambiguate questions about network reliability and in our third study, to ISP address space usage dynamics.

Guillermo’s PhD work was supported by NSF grants CNS-1806785, CNS-2007106 and NSF-2028279 and DH S&T Cyber Security Division contract 70RSAT18CB0000014 and a DHS contract administred by AFRL as contract FA8750-18-2-0280, to USC Viterbi, the Armada de Chile, and the Agencia Nacional de Investigación y Desarrollo de Chile (ANID).

Please see his individual publications for what data is available from his research; his results are also in use in ongoing Trinocular outage detection datasets.

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Students Uncategorized

congratulations to Manaf Gharaibeh for his PhD

I would like to congratulate Dr. Manaf Gharaibeh for defending his PhD at Colorado State University in February 2020 and completing his doctoral dissertation “Characterizing the Visible Address Space to Enable Efficient, Continuous IP Geolocation” in March 2020.

From the abstract:

Manaf Gharaibeh’s phd defense, with Christos Papadopoulos.

Internet Protocol (IP) geolocation is vital for location-dependent applications and many network research problems. The benefits to applications include enabling content customization, proximal server selection, and management of digital rights based on the location of users, to name a few. The benefits to networking research include providing geographic context useful for several purposes, such as to study the geographic deployment of Internet resources, bind cloud data to a location, and to study censorship and monitoring, among others.
The measurement-based IP geolocation is widely considered as the state-of-the-art client-independent approach to estimate the location of an IP address. However, full measurement-based geolocation is prohibitive when applied continuously to the entire Internet to maintain up-to-date IP-to-location mappings. Furthermore, many IP address blocks rarely move, making it unnecessary to perform such full geolocation.
The thesis of this dissertation states that \emph{we can enable efficient, continuous IP geolocation by identifying clusters of co-located IP addresses and their location stability from latency observations.} In this statement, a cluster indicates a group of an arbitrary number of adjacent co-located IP addresses (a few up to a /16). Location stability indicates a measure of how often an IP block changes location. We gain efficiency by allowing IP geolocation systems to geolocate IP addresses as units, and by detecting when a geolocation update is required, optimizations not explored in prior work. We present several studies to support this thesis statement.
We first present a study to evaluate the reliability of router geolocation in popular geolocation services, complementing prior work that evaluates end-hosts geolocation in such services. The results show the limitations of these services and the need for better solutions, motivating our work to enable more accurate approaches. Second, we present a method to identify clusters of \emph{co-located} IP addresses by the similarity in their latency. Identifying such clusters allows us to geolocate them efficiently as units without compromising accuracy. Third, we present an efficient delay-based method to identify IP blocks that move over time, allowing us to recognize when geolocation updates are needed and avoid frequent geolocation of the entire Internet to maintain up-to-date geolocation. In our final study, we present a method to identify cellular blocks by their distinctive variation in latency compared to WiFi and wired blocks. Our method to identify cellular blocks allows a better interpretation of their latency estimates and to study their geographic properties without the need for proprietary data from operators or users.

Categories
Publications Students

congratulations to Lan Wei for her new PhD

I would like to congratulate Dr. Lan Wei for defending her PhD in September 2020 and completing her doctoral dissertation “Anycast Stability, Security and Latency in The Domain Name System (DNS) and Content Deliver Networks (CDNs)” in December 2020.

From the abstract:

Clients’ performance is important for both Content-Delivery Networks (CDNs) and the Domain Name System (DNS). Operators would like the service to meet expectations of their users. CDNs providing stable connections will prevent users from experiencing downloading pause from connection breaks. Users expect DNS traffic to be secure without being intercepted or injected. Both CDN and DNS operators care about a short network latency, since users can become frustrated by slow replies.


Many CDNs and DNS services (such as the DNS root) use IP anycast to bring content closer to users. Anycast-based services announce the same IP address(es) from globally distributed sites. In an anycast infrastructure, Internet routing protocols will direct users to a nearby site naturally. The path between a user and an anycast site is formed on a hop-to-hop basis—at each hop} (a network device such as a router), routing protocols like Border Gateway Protocol (BGP) makes the decision about which next hop to go to. ISPs at each hop will impose their routing policies to influence BGP’s decisions. Without globally knowing (also unable to modify) the distributed information of BGP routing table of every ISP on the path, anycast infrastructure operators are unable to predict and control in real-time which specific site a user will visit and what the routing path will look like. Also, any change in routing policy along the path may change both the path and the site visited by a user. We refer to such minimal control over routing towards an anycast service, the uncertainty of anycast routing. Using anycast spares extra traffic management to map users to sites, but can operators provide a good anycast-based service without precise control over the routing?


This routing uncertainty raises three concerns: routing can change, breaking connections; uncertainty about global routing means spoofing can go undetected, and lack of knowledge of global routing can lead to suboptimal latency. In this thesis, we show how we confirm the stability, how we confirm the security, and how we improve the latency of anycast to answer these three concerns. First, routing changes can cause users to switch sites, and therefore break a stateful connection such as a TCP connection immediately. We study routing stability and demonstrate that connections in anycast infrastructure are rarely broken by routing instability. Of all vantage points (VPs), fewer than 0.15% VP’s TCP connections frequently break due to timeout in 5s during all 17 hours we observed. We only observe such frequent TCP connection break in 1 service out of all 12 anycast services studied. A second problem is DNS spoofing, where a third-party can intercept the DNS query and return a false answer. We examine DNS spoofing to study two aspects of security–integrity and privacy, and we design an algorithm to detect spoofing and distinguish different mechanisms to spoof anycast-based DNS. We show that DNS spoofing is uncommon, happening to only 1.7% of all VPs, although increasing over the years. Among all three ways to spoof DNS–injections, proxies, and third-party anycast site (prefix hijack), we show that third-party anycast site is the least popular one. Last, diagnosing poor latency and improving the latency can be difficult for CDNs. We develop a new approach, BAUP (bidirectional anycast unicast probing), which detects inefficient routing with better routing replacement provided. We use BAUP to study anycast latency. By applying BAUP and changing peering policies, a commercial CDN is able to significantly reduce latency, cutting median latency in half from 40ms to 16ms for regional users.

Lan defended her PhD when USC was on work-from-home due to COVID-19; she is the third ANT student with a fully on-line PhD defense.

Categories
Papers Publications

new journal paper “Detecting IoT Devices in the Internet” in IEEE/ACM Transactions on Networking

We have published a new journal paper “Detecting IoT Devices in the Internet” in IEEE/ACM Transactions on Networking, available at https://www.isi.edu/~johnh/PAPERS/Guo20c.pdf

Figure 5 from [Guo20c] showing per-device-type AS penetrations from 2013 to 2018 for 16 of the 23 device types we studies (omitting 7 device types appearing in less than10 ASes)

From the abstract of our journal paper:

Distributed Denial-of-Service (DDoS) attacks launched from compromised Internet-of-Things (IoT) devices have shown how vulnerable the Internet is to largescale DDoS attacks. To understand the risks of these attacks requires learning about these IoT devices: where are they? how many are there? how are they changing? This paper describes three new methods to find IoT devices on the Internet: server IP addresses in traffic, server names in DNS queries, and manufacturer information in TLS certificates. Our primary methods (IP addresses and DNS names) use knowledge of servers run by the manufacturers of these devices. Our third method uses TLS certificates obtained by active scanning. We have applied our algorithms to a number of observations. With our IP-based algorithm, we report detections from a university campus over 4 months and from traffic transiting an IXP over 10 days. We apply our DNS-based algorithm to traffic from 8 root DNS servers from 2013 to 2018 to study AS-level IoT deployment. We find substantial growth (about 3.5×) in AS penetration for 23 types of IoT devices and modest increase in device type density for ASes detected with these device types (at most 2 device types in 80% of these ASes in 2018). DNS also shows substantial growth in IoT deployment in residential households from 2013 to 2017. Our certificate-based algorithm finds 254k IP cameras and network video recorders from 199 countries around the world.

We make operational traffic we captured from 10 IoT devices we own public at https://ant.isi.edu/datasets/iot/. We also use operational traffic of 21 IoT devices shared by University of New South Wales at http://149.171.189.1/.

This journal paper is joint work of Hang Guo and  John Heidemann from USC/ISI.

Categories
Data

fighting bit rot in log-term data archives with babarchive

As part of research at ANT we generate a lot of data, and our goal is to keep it safe even in the face of an imperfect world of data storage.

When we say a lot, we mean hundreds of terabytes: As of May 2020, we have releasable 860 datasets making up 134 TB of storage (510TB if we uncompressed it). We provide this data at no cost to researchers, and since 2008 we’ve provided 2049 datasets (338 TB, or 1.1PB if uncompressed!) to 406 researchers!

These datasets range from packet captures of “normal” traffic, to curated captures of DDoS attacks, as well as dozens of research paper-specific datasets, 16 years of Internet censuses and 7 years of Internet outages, plus target lists for IPv4 that are regularly used for traffic studies and tools like Verfploeter anycast mapping.

As part of keeping this data, our goal is to keep this data. We want to fight bit rot and data loss. That means the RAID-6 for primary storage, with monitoring and timely disk replacement. It means off site backup (with a big thanks to our collaborators at Colorado State University, Christos Papadopoulos, Craig Partridge, and Dimitrios Kounalakis for their help). And it means watching bits to make sure they don’t spontaneously change.

One might think that bits at rest stay at rest, but… not always. We’ve seen three times when disks have spontaneously changed a byte over the last 20 years. In 2011 and 2012 I had bit flips on my personal files, and in 2020 we had a byte flip on a packet capture.

How do we know? We have application-level checksums of every file, and every day we take 10 minutes to check at least one dataset against its checksums. (Over time, we cover all datasets and then start all over.)

Our checksumming software is babarchive–our own wrapper around collecting SHA-256 checksums over a directory tree. We encourage other researchers interested in long-term data curation to carry out active content monitoring (in addition to backups and RAID).

A huge thanks to our research sponsors: DHS (through the LANDER, LACREND, and LACANIC projects), NSF (through the MADCAT, MR-Net), and DARPA (through GAWSEED).

Categories
Publications Technical Report

new technical report: IoTSTEED: Bot-side Defense to IoT-based DDoS Attacks (Extended)

We have released a new technical report IoTSTEED: Bot-side Defense to IoT-based DDoS Attacks (Extended) as ISI-TR-738, available at https://www.isi.edu/~hangguo/papers/Guo20a.pdf.

From the abstract:

We show IoTSTEED runs
well on a commodity router: memory usage is small (4% of 512MB) and the router forwards traffic at full uplink rates despite about 50% of CPU usage.

We propose IoTSTEED, a system running in edge routers to defend against Distributed Denial-of-Service (DDoS) attacks launched from compromised Internet-of-Things (IoT) devices. IoTSTEED watches traffic that leaves and enters the home network, detecting IoT devices at home, learning the benign servers they talk to, and filtering their traffic to other servers as a potential DDoS attack. We validate IoTSTEED’s accuracy and false positives (FPs) at detecting devices, learning servers and filtering traffic with replay of 10 days of benign traffic captured from an IoT access network. We show IoTSTEED correctly detects all 14 IoT and 6 non-IoT devices in this network (100% accuracy) and maintains low false-positive rates when learning the servers IoT devices talk to (flagging 2% benign servers as suspicious) and filtering IoT traffic (dropping only 0.45% benign packets). We validate IoTSTEED’s true positives (TPs) and false negatives (FNs) in filtering attack traffic with replay of real-world DDoS traffic. Our experiments show IoTSTEED mitigates all typical attacks, regardless of the attacks’ traffic types, attacking devices and victims; an intelligent adversary can design to avoid detection in a few cases, but at the cost of a weaker attack. Lastly, we deploy IoTSTEED in NAT router of an IoT access network for 10 days, showing reasonable resource usage and verifying our testbed experiments for accuracy and learning in practice.

We share 10-day operational traffic captured from 14 IoT devices we own at https://ant.isi.edu/datasets/iot/ (see IoT_Operation_Traces-20200127) and release source code for IoTSTEED at https://ant.isi.edu/software/iotsteed/index.html.

This technical report is joint work of Hang Guo and John Heidemann from USC/ISI.

Categories
Students

congratulations to Calvin Ardi for his new PhD

I would like to congratulate Dr. Calvin Ardi for defending his PhD in April 2020 and completing his doctoral dissertation “Improving Network Security through Collaborative Sharing” in June 2020.

From the abstract:

Calvin Ardi and John Heidemann (inset), after Calvin filed his PhD dissertation.

As our world continues to become more interconnected through the
Internet, cybersecurity incidents are correspondingly increasing in
number, severity, and complexity. The consequences of these attacks
include data loss, financial damages, and are steadily moving from the
digital to the physical world, impacting everything from public
infrastructure to our own homes. The existing mechanisms in
responding to cybersecurity incidents have three problems: they
promote a security monoculture, are too centralized, and are too slow.


In this thesis, we show that improving one’s network security strongly
benefits from a combination of personalized, local detection, coupled
with the controlled exchange of previously-private network information
with collaborators. We address the problem of a security monoculture
with personalized detection, introducing diversity by tailoring to the
individual’s browsing behavior, for example. We approach the problem
of too much centralization by localizing detection, emphasizing
detection techniques that can be used on the client device or local
network without reliance on external services. We counter slow
mechanisms by coupling controlled sharing of information with
collaborators to reactive techniques, enabling a more efficient
response to security events.


We prove that we can improve network security by demonstrating our
thesis with four studies and their respective research contributions
in malicious activity detection and cybersecurity data sharing. In
our first study, we develop Content Reuse Detection, an approach to
locally discover and detect duplication in large corpora and apply our
approach to improve network security by detecting “bad
neighborhoods” of suspicious activity on the web. Our second study
is AuntieTuna, an anti-phishing browser tool that implements personalized,
local detection of phish with user-personalization and improves
network security by reducing successful web phishing attacks. In our
third study, we develop Retro-Future, a framework for controlled information
exchange that enables organizations to control the risk-benefit
trade-off when sharing their previously-private data. Organizations
use Retro-Future to share data within and across collaborating organizations,
and improve their network security by using the shared data to
increase detection’s effectiveness in finding malicious activity.
Finally, we present AuntieTuna2.0 in our fourth study, extending the proactive
detection of phishing sites in AuntieTuna with data sharing between friends.
Users exchange previously-private information with collaborators to
collectively build a defense, improving their network security and
group’s collective immunity against phishing attacks.

Calvin defended his PhD when USC was on work-from-home due to COVID-19; he is the second ANT student with a fully on-line PhD defense.

Categories
Papers Publications

New paper “Bidirectional Anycast/Unicast Probing (BAUP): Optimizing CDN Anycast” at IFIP TMA 2020

We published a new paper “Bidirectional Anycast/Unicast Probing (BAUP): Optimizing CDN Anycast” by Lan Wei (University of Southern California/ ISI), Marcel Flores (Verizon Digital Media Services), Harkeerat Bedi (Verizon Digital Media Services), John Heidemann (University of Southern California/ ISI) at Network Traffic Measurement and Analysis Conference 2020.

From the abstract:

IP anycast is widely used today in Content Delivery Networks (CDNs) and for Domain Name System (DNS) to provide efficient service to clients from multiple physical points-of-presence (PoPs). Anycast depends on BGP routing to map users to PoPs, so anycast efficiency depends on both the CDN operator and the routing policies of other ISPs. Detecting and diagnosing
inefficiency is challenging in this distributed environment. We propose Bidirectional Anycast/Unicast Probing (BAUP), a new approach that detects anycast routing problems by comparing anycast and unicast latencies. BAUP measures latency to help us identify problems experienced by clients, triggering traceroutes to localize the cause and suggest opportunities for improvement. Evaluating BAUP on a large, commercial CDN, we show that problems happens to 1.59% of observers, and we find multiple opportunities to improve service. Prompted by our work, the CDN changed peering policy and was able to significantly reduce latency, cutting median latency in half (40 ms to 16 ms) for regions with more than 100k users.

The data from this paper is publicly available from RIPE Atlas, please see paper reference for measurement IDs.

Categories
Students

congratulations to Hang Guo for his new PhD

I would like to congratulate Dr. Hang Guo for defending his PhD in April 2020 and completing his doctoral dissertation “Detecting and Characterizing Network Devices Using
Signatures of Traffic About End-Points” in May 2020.

Hang Guo and John Heidemann (inset), after Hang filed his PhD dissertation.

From the abstract:

The Internet has become an inseparable part of our society. Since the Internet is essentially a distributed system of billions of inter-connected, networked devices, learning about these devices is essential for better understanding, managing and securing the Internet. To study these network devices, without direct control over them or direct contact with their users, requires traffic-based methods for detecting devices. To identify target devices from traffic measurements, detection of network devices relies on signatures of traffic, mapping from certain characteristics of traffic to target devices. This dissertation focuses on device detection that use signatures of traffic about end-points: mapping from characteristics of traffic end-point, such as counts and identities, to target devices. The thesis of this dissertation is that new signatures of traffic about end-points enable detection and characterizations of new class of network devices. We support this thesis statement through three specific studies, each detecting and characterizing a new class of network devices with a new signature of traffic about end-points. In our first study, we present detection and characterization of network devices that rate limit ICMP traffic based on how they change the responsiveness of traffic end-points to active probings. In our second study, we demonstrate mapping identities of traffic end-points to a new class of network devices: Internet-of-Thing (IoT) devices. In our third study, we explore detecting compromised IoT devices by identifying IoT devices talking to suspicious end-points. Detection of these compromised IoT devices enables us to mitigate DDoS traffic between them and suspicious end-points.

Hang defend his PhD when USC was on work-from-home due to COVID-19, so he is the first ANT student with a fully on-line PhD defense.

Categories
Presentations

new talk “A First Look at Measuring the Internet during Novel Coronavirus to Evaluate Quarantine (MINCEQ)” at Digital Technologies for COVID-19 Webinar Series

John Heidemann gave the talk “A First Look at Measuring the Internet during Novel Coronavirus to Evaluate Quarantine (MINCEQ)” at Digital Technologies for COVID-19 Webinar Series, hosted by Craig Knoblock and Bhaskar Krishnamachari of USC Viterbi School of Engineering on May 29, 2020. Internet Outages: Reliablity and Security” at the University of Oregon Cybersecurity Day in Eugene, Oregon on April 23, 2018.  A video of the talk is on YoutTube at https://www.youtube.com/watch?v=tduZ1Y_FX0s. Slides are available at https://www.isi.edu/~johnh/PAPERS/Heidemann20a.pdf.

From the abstract:

Measuring the Internet during Novel Coronavirus to Evaluate Quarantine (RAPID-MINCEQ) is a project to measure changes in Internet use during the COVID-19 outbreak of 2020.

Today social distancing and work-from-home/study-from-home are the best tools we have to limit COVID’s spread. But implementation of these policies varies in the US and around the global, and we would like to evaluate participation in these policies.
This project plans to develop two complementary methods of assessing Internet use by measuring address activity and how it changes relative to historical trends. Changes in the Internet can reflect work-from-home behavior. Although we cannot see all IP addresses (many are hidden behind firewalls or home routers), early work shows changes at USC and ISI.


This project is support by an NSF RAPID grant for COVID-19 and just began in May 2020, so this talk will discuss directions we plan to explore.

This project is joint work of Guillermo Baltra, Asma Enayet, John Heidemann, Yuri Pradkin, and Xiao Song and is supported by NSF/CISE as award NSF-2028279.