Materials by Teodor Janez Podobnik

Explore tutorials, challenges, courses, and more published by this author.

Tutorials by Teodor Janez Podobnik

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Tutorial

Hands-On with XDP: eBPF for High-Performance Networking

In this tutorial, you’ll learn the fundamentals of eBPF and XDP through example code that parses packets across different protocol layers, demonstrates how XDP actions work, and shows how these building blocks form the foundation for high-performance networking applications.

Hands-On with XDP: eBPF for High-Performance Networking (cover image)
Tutorial

Network Traffic Rate Limiting with eBPF/XDP

Learn how to implement a basic per-client ICMPv6 packet rate limiter using eBPF/XDP. This tutorial shows how to track client activity with eBPF maps and enforce limits directly in the kernel—without any user-space interaction.

Network Traffic Rate Limiting with eBPF/XDP (cover image)
Tutorial

Why Does My eBPF Program Work on One Kernel but Fail on Another?

In this tutorial, we look at why eBPF programs can fail across kernel versions due to changes in structs, tracepoints, and function layouts. We look at examples of how these differences cause portability issues and how BPF CO-RE, BTF and vmlinux.h address them.

Why Does My eBPF Program Work on One Kernel but Fail on Another? (cover image)

Challenges by Teodor Janez Podobnik

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Challenge,  Easy

eBPF Challenge for Beginners

In this challenge, you’ll debug and fix a deliberately “broken” eBPF program, then prove it’s running by identifying its program and map IDs. Along the way, you’ll explore bpftool, check which helpers are supported, and dig into details like the UID of the loader. Finally, you’ll test your knowledge of eBPF maps by recalling the flag that only inserts a key if it doesn’t already exist.

Submissions: 50/152

Skill Paths by Teodor Janez Podobnik

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Skill Path

eBPF Beginner Skill Path

Learn eBPF from the ground up — from writing and running your first program, to storing data in eBPF maps, inspecting and monitoring kernel activity using bpftool and bpftop, and understanding how the verifier ensures safe eBPF execution. Finish with a hands-on challenge to put your new skills to the test.

  • 4 Tutorials
  • 1 Challenge
  • Easy
Skill Path

eBPF CO-RE Skill Path

In this learning path, you’ll go from comparing different tracing program types — tracepoints, raw tracepoints, kprobes, and fprobes — to writing portable eBPF programs that work reliably across environments. You’ll also understand the role of BTF and learn how to make your eBPF code portable even when BTF isn’t available on the target system.