congratulations to Tarang Saluja for his summer undergraduate research internship

Tarang Saluja completed his summer undergraduate research internship at ISI this summer, working with John Heidemann and Yuri Pradkin on his project “Differences in Monitoring the DNS Root Over IPv4 and IPv6″.

In his project, Tarang examined RIPE Atlas’s DNSmon, a measurement system that monitors the Root Server System. DNSmon examines both IPv4 and IPv6, and its IPv6 reports show query loss rates that are consistently higher than IPv4, often 4-6% IPv6 loss vs. no or 2% IPv4 loss. Prior results by researchers at RIPE suggested these differences were due to problems at specific Atlas Vantage Points (VPs, also called Atlas Probes).

Tarang Saluja describing his research to an ISI researcher, at the ISI REU Poster Session on 2022-08-01.

Building on the Guillero Baltra’s studies of partial connectivity in the Internet, Tarang classified Atlas VPs with problems as islands and peninsulas. Islands think they are on IPv6, but cannot reach any of the 13 Root DNS “letters” over IPv6, indicating that the VP has a local network configuration problem. Peninsulas can reach some letters, but not others, indicating a routing problem somewhere in the core of the Internet.

Tarang’s work is important because these observations allow lead to potential solutions. Islands suggest VPs that do not support IPv6 and so should not be used for monitoring. Peninsulas point to IPv6 routing problems that need to be addressed by ISPs. Setting VPs with these problems aside provides a more accurate view of what IPv6 should be, and allows us to use DNSmon to detect more subtle problems. Together, his work points the way to improving IPv6 for everyone and improving Root DNS access over IPv6.

Tarang’s work was part of the ISI Research Experiences for Undergraduates program at USC/ISI. We thank Jelena Mirkovic (PI) for coordinating another year of this great program, and NSF for support through award #2051101.

Internet Papers Publications Software releases

new paper “Chhoyhopper: A Moving Target Defense with IPv6” at NDSS MADWeb Workshop 2022

On April 24, 2022 we will publish a new paper titled “Chhoyhopper: A Moving Target Defense with IPv6” by A S M Rizvi and John Heidemann at the 4th Workshop on Measurements, Attacks, and Defenses for the Web (MADWeb 2022), co-located with NDSS. We provide Chhoyhopper as an open-source tool for SSH and HTTPS—try it out!

From the abstract:

Services on the public Internet are frequently scanned, then subject to brute-force password attempts and Denial-of-Service (DoS) attacks. We would like to run such services stealthily, where they are available to friends but hidden from adversaries. In this work, we propose a discovery-resistant moving target defense named “Chhoyhopper” that utilizes the vast IPv6 address space to conceal publicly available services. The client meets the server at an IPv6 address that changes in a pattern based on a shared, pre-distributed secret and the time of day. By hopping over a /64 prefix, services cannot be found by active scanners, and passively observed information is useless after two minutes. We demonstrate our system with the two important applications—SSH and HTTPS, and make our system publicly available.

Client and server interaction in Chhoyhopper. A Client with the right secret key can only get access into the system.

Thanks: A S M Rizvi and John Heidemann’s work on this paper is supported, in part, by the DHS HSARPA Cyber Security Division via contract number HSHQDC-17-R-B0004-TTA.02-0006-I (PAADDoS), and by DARPA under Contract No. HR001120C0157 (SABRES). Any opinions, findings and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of NSF or DARPA. We thank Rayner Pais who prototyped an early version of Chhoyhopper and version in IPv4 hopping over ports.