Tag: datasets

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Publications Technical Report

new technical report “Verfploeter: Broad and Load-Aware Anycast Mapping”

We have released a new technical report “Verfploeter: Broad and Load-Aware Anycast Mapping”,by Wouter B. de Vries, Ricardo de O. Schmidt, Wes Haraker, John Heidemann, Pieter-Tjerk de Boer, and Aiko Pras as an ISI technical report ISI-TR-717.

Verfploeter coverage of B-Root. Circle radiuses are how many /24 blocks in each 2×2 degree region go to B-Root, and colored slices indicate which go to LAX and which to MIA. (Figure 2b from [Vries17a], dataset: SBV-5-15).
From the abstract:

IP anycast provides DNS operators and CDNs with automatic fail-over and reduced latency by breaking the Internet into catchments, each served by a different anycast site. Unfortunately, understanding and predicting changes to catchments as sites are added or removed has been challenging. Current tools such as RIPE Atlas or commercial equivalents map from thousands of vantage points (VPs), but their coverage can be inconsistent around the globe. This paper proposes Verfploeter, a new method that maps anycast catchments using active probing. Verfploeter provides around 3.8M virtual VPs, 430x the 9k physical VPs in RIPE Atlas, providing coverage of the vast majority of networks around the globe.  We then add load information from prior service logs to provide calibrated predictions of anycast changes. Verfploeter has been used to evaluate the new anycast for B-Root, and we also report its use of a 9-site anycast testbed. We show that the greater coverage made possible by Verfploeter’s active probing is necessary to see routing differences in regions that have sparse coverage from RIPE Atlas, like South America and China.

All datasets used in this paper (but one) are available at https://ant.isi.edu/datasets/anycast/index.html#verfploeter .

 

Categories
Publications Technical Report

new technical report “Detecting ICMP Rate Limiting in the Internet”

We have released a new technical report “Detecting ICMP Rate Limiting in the Internet” as an ISI technical report ISI-TR-717.

From the abstract of our technical report:

Comparing model and experimental effects of rate limiting (Figure 2.a from [Guo17a] )

Active probing with ICMP is the center of many network measurements, with tools like ping, traceroute, and their derivatives used to map topologies and as a precursor for security scanning. However, rate limiting of ICMP traffic has long been a concern, since undetected rate limiting to ICMP could distort measurements, silently creating false conclusions. To settle this concern, we look systematically for ICMP rate limiting in the Internet. We develop a model for how rate limiting affects probing, validate it through controlled testbed experiments, and create FADER, a new algorithm that can identify rate limiting from user-side traces with minimal requirements for new measurement traffic. We validate the accuracy of FADER with many different network configurations in testbed experiments and show that it almost always detects rate limiting. Accuracy is perfect when measurement probing ranges from 0 to 60 times the rate limit, and almost perfect (95%) with up to 20% packet loss. The worst case for detection is when probing is very fast and blocks are very sparse, but even there accuracy remains good (measurements 60 times the rate limit of a 10% responsive block is correct 65% of the time). With this confidence, we apply our algorithm to a random sample of whole Internet, showing that rate limiting exists
but that for slow probing rates, rate-limiting is very, very rare. For our random sample of 40,493 /24 blocks (about 2\% of the responsive space), we confirm 6 blocks (0.02%!) see rate limiting
at 0.39 packets/s per block. We look at higher rates in public datasets
and suggest that fall-off in responses as rates approach 1 packet/s per /24 block (14M packets/s from the prober to the whole Internet),
is consistent with rate limiting. We also show that even very slow probing (0.0001 packet/s) can encounter rate limiting of NACKs that are concentrated at a single router near the prober.

Datasets we used in this paper are all public. ISI Internet Census and Survey data (including it71w, it70w, it56j, it57j and it58j census and survey) are available at https://ant.isi.edu/datasets/index.html. ZMap 50-second experiments data are from their WOOT 14 paper and can be obtained from ZMap authors upon request.

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

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Papers Publications

new conference paper “Does Anycast Hang up on You?” in TMA 2017

The paper “Does Anycast hang up on you?” will appear in the 2017 Conference on Network Traffic Measurement and Analysis (TMA) July 21-23, 2017 in Dublin, Ireland.

In each anycast-based DNS root service, there are about 1% VPs see a route flip happens every one or two observation during a week with an observation interval as 4 minutes. (Figure 2 from [Wei17b]).
From the abstract:

Anycast-based services today are widely used commercially, with several major providers serving thousands of important websites. However, to our knowledge, there has been only limited study of how often anycast fails because routing changes interrupt connections between users and their current anycast site. While the commercial success of anycast CDNs means anycast usually work well, do some users end up shut out of anycast? In this paper we examine data from more than 9000 geographically distributed vantage points (VPs) to 11 anycast services to evaluate this question. Our contribution is the analysis of this data to provide the first quantification of this problem, and to explore where and why it occurs. We see that about 1\% of VPs are anycast unstable, reaching a different anycast site frequently (sometimes every query). Flips back and forth between two sites in 10 seconds are observed in selected experiments for given service and VPs. Moreover, we show that anycast instability is persistent for some VPs—a few VPs never see a stable connections to certain anycast services during a week or even longer. The vast majority of VPs only saw unstable routing towards one or two services instead of instability with all services, suggesting the cause of the instability lies somewhere in the path to the anycast sites. Finally, we point out that for highly-unstable VPs, their probability to hit a given site is constant, which means the flipping are happening at a fine granularity—per packet level, suggesting load balancing might be the cause to anycast routing flipping. Our findings confirm the common wisdom that anycast almost always works well, but provide evidence that a small number of locations in the Internet where specific anycast services are never stable.

This paper is joint work of Lan Wei and John Heidemann.  A pre-print of paper is at http://ant.isi.edu/~johnh/PAPERS/Wei17b.pdf, and the datasets from the paper are at https://ant.isi.edu/datasets/anycast/index.html#stability.

Categories
Papers Publications

new conference paper “Do You See Me Now? Sparsity in Passive Observations of Address Liveness” in TMA 2017

The paper “Do You See Me Now? Sparsity in Passive Observations of Address Liveness” will appear in the 2017 Conference on Network Traffic Measurement and Analyais (TMA) July 21-23, 2017 in Dublin, Ireland.   The datasets from the paper that we can make public will be at https://ant.isi.edu/datasets/sparsity/.

Visibility of addresses and blocks from possible /24 virtual monitors (Figure 2 from [Mirkovic17a])
From the abstract of the paper:

Accurate information about address and block usage in the Internet has many applications in planning address allocation, topology studies, and simulations. Prior studies used active probing, sometimes augmented with passive observation, to study macroscopic phenomena, such as the overall usage of the IPv4 address space. This paper instead studies the completeness of passive sources: how well they can observe microscopic phenomena such as address usage within a given network. We define sparsity as the limitation of a given monitor to see a target, and we quantify the effects of interest, temporal, and coverage sparsity. To study sparsity, we introduce inverted analysis, a novel approach that uses complete passive observations of a few end networks (three campus networks in our case) to infer what of these networks would be seen by millions of virtual monitors near their traffic’s destinations. Unsurprisingly, we find that monitors near popular content see many more targets and that visibility is strongly influenced by bipartite traffic between clients and servers. We are the first to quantify these effects and show their implications for the study of Internet liveness from passive observations. We find that visibility is heavy-tailed, with only 0.5% monitors seeing more than 10\% of our targets’ addresses, and is most affected by interest sparsity over temporal and coverage sparsity. Visibility is also strongly bipartite. Monitors of a different class than a target (e.g., a server monitor observing a client target) outperform monitors of the same class as a target in 82-99% of cases in our datasets. Finally, we find that adding active probing to passive observations greatly improves visibility of both server and client target addresses, but is not critical for visibility of target blocks. Our findings are valuable to understand limitations of existing measurement studies, and to develop methods to maximize microscopic completeness in future studies.

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Announcements Collaborations Papers

best paper award at PAM 2017

The PAM 2017 best paper award for “Anycast Latency: How Many Sites Are Enough?”

Congratulations to Ricardo de Oliveira Schmidt (U. Twente), John Heidemann (USC/ISI), and Jan Harm Kuipers (U. Twente) for the award of  best paper at the Conference on Passive and Active Measurement (PAM) 2017 to their paper “Anycast Latency: How Many Sites Are Enough?”.

See our prior blog post for more information about the paper and its data, and the U. Twente blog post about the paper and the SIDN Labs blog post about the paper.

Categories
Presentations

new talk “Collecting and Visualizing Outages Over the Long Haul” at the AIMS Workshop 2017

John Heidemann gave the talk “Collecting and Visualizing Outages Over the Long Haul” at CAIDA’s Active Internet Measurement (AIMS) Workshop in San Diego, California, USA on March 2, 2017.  Slides are available at http://www.isi.edu/~johnh/PAPERS/Heidemann17b.pdf.
From the abstract:

Unmeasurable blocks over time, a challenge in long-haul outage measurement, from [Alwabel15a]
We have been collecting data about outages in the Internet since Oct. 2014. Our outage detection system, Trinocular, uses active probing from four sites to study about 4 million /24 IPv4 address blocks. Long-duration measurements bring challenges that don’t occur in short observations. Most importantly, our target (“the Internet”) changes as we measure it, as new blocks come on-line, old blocks are reused in different ways, and ISPs observe and sometimes block our traffic. Our measurement platform also sees occasional hardware failures. Visualization can assist detection of these problems, allowing human perception to detect changes in data collection that have not previously been anticipated. This talk will discuss the challenges of long-term outage measurement and describe our new algorithm that scales to support clustering of 4M blocks and 3 months of observations for visualization.
Our visualization is joint work with Yuri Pradkin, and analysis of our long-term outages includes work with Abdulla Alwabel.

This talk draws on work from [Alwabel15a].  Data from this talk is available at https://ant.isi.edu/datasets/outage/, and visualizations can be found at https://ant.isi.edu/outage/browse/.

Categories
Publications Technical Report

new technical report “Does Anycast hang up on You? (extended)”

We have released a new technical report “Does Anycast hang up on you?(extended)”, ISI-TR-716, available at http://www.isi.edu/~weilan/PAPER/anycast_instability.pdf

From the abstract:

In each anycast-based DNS root service, there are about 1% VPs see a route flip happens every one or two observation during a week with an observation interval as 4 min.

Anycast-based services today are widely used commercially, with several major providers serving thousands of important websites. However, to our knowledge, there has been only limited study of how often anycast fails because routing changes interrupt connections between users and their current anycast site. While the commercial success of anycast CDNs means anycast usually work well, do some users end up shut out of anycast? In this paper we examine data from more than 9000 geographically distributed vantage points (VPs) to 11 anycast services to evaluate this question. Our contribution is the analysis of this data to provide the first quantification of this problem, and to explore where and why it occurs. We see that about 1% of VPs are anycast unstable, reaching a different anycast site frequently sometimes every query. Flips back and forth between two sites in 10 seconds are observed in selected experiments for given service and VPs.
Moreover, we show that anycast instability is persistent for some VPs—a few VPs never see a stable connections to certain anycast services during a week or even longer. The vast majority of VPs only saw unstable routing towards one or two services instead of instability with all services, suggesting the cause of the instability lies somewhere in the path to the anycast sites. Finally, we point out that for highly-unstable VPs, their probability to hit a given site is constant, which means the flipping are happening at a fine granularity —per packet level, suggesting load balancing might be the cause to anycast routing flipping. Our findings confirm the common wisdom that anycast almost always works well, but provide evidence that a small number of locations in the Internet where specific anycast services are never stable.

This technical report is joint work of  Lan Wei,  John Heidemann, from USC/ISI.

Categories
Papers Publications

new conference paper “Anycast Latency: How Many Sites Are Enough?” in PAM 2017

The paper “Anycast Latency: How Many Sites Are Enough?” will appear at PAM 2017, the Conference on Passive and Active Measurement in March 2017 in Sydney, Australia (available at http://www.isi.edu/~johnh/PAPERS/Schmidt17a.pdf)

Update 2017-03-31:  This paper was awarded Best Paper at PAM 2017.

Median RTT (with quartiles as error bars) for countries with at least 5 vantage points for L-Root in 2015. Even more than 100 anycast sites, L still has relatively high latency in some countries in Africa and Asia.

 

 

 

From the abstract:

Anycast is widely used today to provide important services such as DNS and Content Delivery Networks (CDNs). An anycast service uses multiple sites to provide high availability, capacity and redundancy. BGP routing associates users to sites, defining the catchment that each site serves. Although prior work has studied how users associate with anycast services informally, in this paper we examine the key question how many anycast sites are needed to provide good latency, and the worst case latencies that specific deployments see. To answer this question, we first define the optimal performance that is possible, then explore how routing, specific anycast policies, and site location affect performance. We develop a new method capable of determining optimal performance and use it to study four real-world anycast services operated by different organizations: C-, F-, K-, and L-Root, each part of the Root DNS service. We measure their performance from more than 7,900 vantage points (VPs) worldwide using RIPE Atlas. (Given the VPs uneven geographic distribution, we evaluate and control for potential bias.) Our key results show that a few sites can provide performance nearly as good as many, and that geographic location and good connectivity have a far stronger effect on latency than having many sites. We show how often users see the closest anycast site, and how strongly routing policy affects site selection.

This paper is joint work of  Ricardo de Oliveira Schmidt, John Heidemann (USC/ISI), and Jan Harm Kuipers (U. Twente).  Datasets in this paper are derived from RIPE Atlas and are available at http://traces.simpleweb.org/ and at https://ant.isi.edu/datasets/anycast/.

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Presentations

new talk “Distributed Denial-of-Service: What Datasets Can Help?” at ACSAC 2016

John Heidemann gave the talk “Distributed Denial-of-Service: What Datasets Can Help?” at ACSAC 2016 in Universal City, California, USA on December 7, 2016.  Slides are available at http://www.isi.edu/~johnh/PAPERS/Heidemann16d.pdf.

heidemann16d_iconFrom the abstract:

Distributed Denial-of-Service attacks are continuing threat to the Internet. Meeting this threat requires new approaches that will emerge from new research, but new research requires the support of dataset and experimental methods. This talk describes four different aspects of research on DDoS, privacy and security, and the datasets that have generated to support that research. Areas we consider are detecting low rate DDoS attacks, understanding the effects of DDoS on DNS infrastructure, evolving the DNS protocol to prevent DDoS and improve privacy, and ideas about experimental testbeds to evaluate new ideas in DDoS defense for DNS. Datasets described in this talk are available at no cost from the author and through the IMPACT Program.

This talk is based on the work with many prior collaborators: Terry Benzel, Wes Hardaker, Christian Hessleman, Zi Hu, Allison Mainkin, Urbashi Mitra, Giovane Moura, Moritz Müller, Ricardo de O. Schmidt, Nikita Somaiya, Gautam Thatte, Wouter de Vries, Lan Wei, Duane Wessels, Liang Zhu.

Datasets from the paper are available at https://ant.isi.edu/datasets/ and at https://impactcybertrust.org.

Categories
Presentations

new talk “Anycast vs. DDoS: Evaluating Nov. 30” at DNS-OARC

John Heidemann gave the talk “Anycast vs. DDoS: Evaluating Nov. 30” at DNS-OARC in Dallas, Texas, USA on October 16, 2016.  Slides are available at http://www.isi.edu/~johnh/PAPERS/Heidemann16c.pdf.

 

Possible outcomes of anycast under stress, a slide from a talk about the Nov. 30, 2015 Root DNS event.
Possible outcomes of anycast under stress, a slide from a talk about the Nov. 30, 2015 Root DNS event.

From the abstract:

Distributed Denial-of-Service (DDoS) attacks continue to be a major threat in the Internet today. DDoS attacks overwhelm target services with requests or other “bogus” traffic, causing requests from legitimate users to be shut out. A common defense against DDoS is to replicate the service in multiple physical locations or sites. If all sites announce a common IP address, BGP will associate users around the Internet with a nearby site, defining the catchment of that site. Anycast adds resilience against DDoS both by increasing capacity to the aggregate of many sites, and allowing each catchment to contain attack traffic leaving other sites unaffected. IP anycast is widely used for commercial CDNs and essential infrastructure such as DNS, but there is little evaluation of anycast under stress.

This talk will provide a first evaluation of several anycast services under stress with public data. Our subject is the Internet’s Root Domain Name Service, made up of 13 independently designed services (“letters”, 11 with IP anycast) running at more than 500 sites. Many of these services were stressed by sustained traffic at 100x normal load on Nov. 30 and Dec. 1, 2015. We use public data for most of our analysis to examine how different services respond to the these events. In our analysis we identify two policies by operators: (1) sites may absorb attack traffic, containing the damage but reducing service to some users, or (2) they may withdraw routes to shift both legitimate and bogus traffic to other sites. We study how these deployment policies result in different levels of service to different users, during and immediately after the attacks.

We also show evidence of collateral damage on other services located near the attack targets. The work is based on analysis of DNS response from around 9000 RIPE Atlas vantage points (or “probes”), agumented by RSSAC-002 reports from 5 root letters and BGP data from BGPmon. We examine DNS performance for each Root Letter, for anycast sites inside specific letters, and for specific servers at one site.

This talk is based on the work in the paper “Anycast vs. DDoS: Evaluating the November 2015 Root DNS Event” at appear at  IMC 2016, by Giovane C. M. Moura, Ricardo de O. Schmidt, John Heidemann, Wouter B. de Vries, Moritz Müller,  Lan Wei, and Christian Hesselman.

Datasets from the paper are available at https://ant.isi.edu/datasets/anycast/