Month: October 2017

Categories
Presentations

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

Wes Hardaker gave the talk “Verfploeter: Broad and Load-Aware Anycast Mapping” at DNS-OARC in San Jose, California, USA on September 29, 2017.  Slides are available at on the event page.

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, 430 times 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 nine-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.

 

A video of the talk is available On YouTube.

Categories
DNS Papers Publications

new journal paper “Detecting Malicious Activity With DNS Backscatter Over Time” in IEEE/ACM ToN Oct, 2017

The paper “Detecting Malicious Activity With DNS Backscatter Over Time ” appears in EEE/ACM  Transactions on Networking ( Volume: 25, Issue: 5, Oct. 2017 ).

From the abstract:

Network-wide activity is when one computer (the originator) touches many others (the targets). Motives for activity may be benign (mailing lists, CDNs, and research scanning), malicious (spammers and scanners for security vulnerabilities), or perhaps indeterminate (ad trackers). Knowledge of malicious activity may help anticipate attacks, and understanding benign activity may set a baseline or characterize growth. This paper identifies DNS backscatter as a new source of information about network-wide activity. Backscatter is the reverse DNS queries caused when targets or middleboxes automatically look up the domain name of the originator. Queries are visible to the authoritative DNS servers that handle reverse DNS. While the fraction of backscatter they see depends on the server’s location in the DNS hierarchy, we show that activity that touches many targets appear even in sampled observations. We use information about the queriers to classify originator activity using machine learning. Our algorithm has reasonable accuracy and precision (70–80%) as shown by data from three different organizations operating DNS servers at the root or country-level. Using this technique we examine nine months of activity from one authority to identify trends in scanning, identifying bursts corresponding to Heartbleed and broad and continuous scanning of ssh.

This paper furthers our understanding of evolution of malicious network activities from an earlier work that:
(1) Why our machine-learning based classifier (that relies on manually collected labeled data) does not port across physical sites and over time.
(2) Secondly paper recommends how to sustain good learning score over time and provides expected life-time of labeled data.

An excerpt from section III-E (Training Over Time):

Classification (§ III-D) is based on training, yet training accuracy is affected by the evolution of activity—specific examples come and go, and the behavior in each class evolves. Change happens for all classes, but the problem is particularly acute for malicious classes (such as spam) where the adversarial nature of the action forces rapid evolution (see § V).

 

Some datasets used in this paper can be found here:

Categories
Papers Publications

new conference paper “Recursives in the Wild: Engineering Authoritative DNS Servers” in IMC 2017

The paper “Recursives in the Wild: Engineering Authoritative DNS Servers” will appear in the 2017 Internet Measurement Conference (IMC) on November 1-3, 2017 in London, United Kingdom.

Recursive DNS server selection of authoritatives, per continent. (Figure 4 from [Mueller17b].)
From the abstract:

In In Internet Domain Name System (DNS), services operate authoritative name servers that individuals query through recursive resolvers. Operators strive to provide reliability by operating multiple name servers (NS), each on a separate IP address, and by using IP anycast to allow NSes to provide service from many physical locations. To meet their goals of minimizing latency and balancing load across NSes and anycast, operators need to know how recursive resolvers select an NS, and how that interacts with their NS deployments. Prior work has shown some recursives search for low latency, while others pick an NS at random or round robin, but did not examine how prevalent each choice was. This paper provides the first analysis of how recursives select between name servers in the wild, and from that we provide guidance to operators how to engineer their name servers to reach their goals. We conclude that all NSes need to be equally strong and therefore we recommend to deploy IP anycast at every single authoritative.

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

Categories
Papers Publications

new conference paper “Broad and Load-aware Anycast Mapping with Verfploeter” in IMC 2017

The paper “Broad and Load-aware Anycast Mapping with Verfploeter” will appear in the 2017 Internet Measurement Conference (IMC) on November 1-3, 2017 in London, United Kingdom.

From the abstract:

IP anycast provides DNS operators and CDNs with automatic failover and reduced latency by breaking the Internet into catchments, each served by a different anycast site. Unfortunately, understanding and predicting changes to catchments as anycast 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 passive 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 deployment for B-Root, and we also report its use of a nine-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.

Distribution of load across two anycast sites of B-root using Verfploeter.

The work in this paper was joint work by Wouter B. de Vries, Ricardo de O. Schmidt (Univ. of Twente), Wes Hardaker, John Heidemann (USC/ISI), Pieter-Tjerk de Boer and Aiko Pras (Univ. of Twente). The datasets used in the paper are available at https://ant.isi.edu/datasets/anycast/index.html#verfploeter.