Hi,

I'm Lars,


a novice scientist,
discussion enthusiast,
& cottage cheese lover.

Contact Me
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I'm a last-year Ph.D. student interested in routing, traffic engineering, and congestion control. I work in Anja Feldmann's group at the Max Planck Institute for Informatics in Saarbrücken and plan to finish my Ph.D. in late 2022. My research combines the quantitive analysis of longitudinal data with active probing campaigns to provide new insights into long-standing research topics. A continuous discourse with network operators allows me to contextualize the implications and importance of my findings and guides me towards new, exciting research endeavors.
Since my second year at the university, I continuously taught younger students. While I started by tutoring 30-40 students on data structures, algorithms, and networking, I recently co-organized multiple networking-related courses for more than 150 students and co-supervised the bachelor or master theses of six students.

After my Ph.D., I look for opportunities to strengthen my current expertise in routing and measurements while extending my knowledge of systems engineering, machine learning, and statistics. If you think I could be a good match for your team, please don't hesitate to ping me!


Publications

Hyper-Specific Prefixes: Gotta Enjoy the Little Things in Interdomain Routing

K. Z. Sediqi, L. Prehn, O. Gasser

Will appear in ACM SIGCOMM Computer Communication Review 53 (2022)

CCR'22

Peering Only? Analyzing the Reachability Benefits of Joining Large IXPs Today

L. Prehn, F. Lichtblau, C. Dietzel, and A. Feldmann

International Conference on Passive and Active Network Measurement (pp. 338-366), 2022.

PDF Video
PAM'22

How biased is our Validation (Data) for AS Relationships?

L. Prehn and A. Feldmann

Proceedings of the ACM Internet Measurement Conference (pp. 612-620), 2021.

PDF Video
IMC'21

When Wells Run Dry: The 2020 IPv4 Address Market

L. Prehn, F. Lichtblau, and A. Feldmann

Proceedings of the 16th International Conference on emerging Networking EXperiments and Technologies (pp. 46-54), 2020.

PDF Video
CoNEXT'20

AS-Path Prepending: there is no rose without a thorn

P. Marcos, L. Prehn, L. Leal, A. Dainotti, A. Feldmann, and M. Barcellos

Proceedings of the ACM Internet Measurement Conference (pp. 506-520), 2020.

PDF Video
IMC'20

Reviewing Experience & Service

Shadow TPC Chair

Anja and I organize the Shadow TPC excercise.

IMC'22

Student Organizer

Amanda and I organized the Student Welcoming Session.

SIGCOMM'21

Member of Artifact Evaluation Commitee

SIGCOMM'21

Student Scribe

during the virtual PC meeting.

CoNEXT'20

Shadow PC Exercise

with an in-person Shadow PC meeting in London.

IMC'19

Education

Ph.D. Student

Max-Planck-Institut für Informatik

Under the guidance of Anja Feldmann, I'm working on topics related to Interdomain routing and its building blocks. More specifically, my current projects aim at better understanding spoofing detection mechanisms, scrubbing service operations, the possibilities of large peering infrastructures, and the enhancement of the route collector infrastructure.

November 2018 - current

M.Sc. in Computer Science

Technische Universität Berlin

October 2017 - October 2018

B.Sc. in Computer Science

Technische Universität Berlin

October 2014 - March 2018

Teaching

Teaching Assistant

Max-Planck-Institut für Informatik

I co-organized Anja Feldmann's seminar "Hot Topics in Data Networks."

Winter Term 2020/21

Teaching Assistant

Max-Planck-Institut für Informatik

I co-organized Anja Feldmann's course "Data Networks."

Summer Term 2020

Student Assistant

Technische Universität Berlin

In Anja Feldmann's course "Network Protocols and Architectures," I assisted the grading for weekly assignments and helped to prepare the exam.

Winter Term 2017/18

Student Assistant

Technische Universität Berlin

In Oliver Brock's course "Algorithms and Data Structures," I presented tutorials to two small groups of about 40 students every week.

Summer Term 2017

Lab Assistant

Technische Universität Berlin

I co-organized and instructed lab sessions as well as graded the bi-weekly assignments for the lab that accompanies Adam Wolisz's "Network Technologies" lecture.

Winter Term 2016/17

Student Assistant

Technische Universität Berlin

In Oliver Brock's course "Algorithms and Data Structures", I presented tutorials to two small groups of about 30 students every week.

Summer Term 2016

Get in touch

Max Planck Institute for Informatics
Saarland Informatics Campus
Campus E1 4
66123 Saarbrücken
Germany