A technical investigation reveals how ECN and ECMP routing caused broken connections to Cloudflare, ultimately resolved by disabling ECMP on the ISP's routers.
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Toke Høiland-Jørgensen is a Linux kernel developer focused on networking and XDP, author of performance tools, with hobbies in music, dancing, and dog care.
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The post critiques departure time-based traffic shaping in BPF data planes, revealing its potential to create latency issues due to a 'virtual FIFO' queueing effect.
This post explores how to use BPF and kprobes to identify which netfilter rule caused a packet drop, highlighting the complexities involved in the process.
This post explains how to bridge WiFi and Ethernet networks on separate subnets while solving DNS service discovery and device identification issues in IPv6 using custom tools.
7.1The XDP traffic generator
2023-05-26 • linux networking ebpf xdp traffic generation
The XDP traffic generator enables high-rate packet generation for UDP and TCP traffic using the BPF_PROG_RUN syscall, showcasing its programmability and performance capabilities.
TCP zero-copy in the Linux kernel optimizes data transmission by eliminating unnecessary memory copying, enhancing throughput for high-speed applications.
eBPF's expanded capabilities allow for deterministic delays in kernel functions, presenting both useful applications and significant risks for system stability.
The open source community calls on the European Commission to sustain funding for the NGI initiative beyond 2025 to support free software and European technological sovereignty.
The post critiques the AI hype, emphasizing its overvaluation, societal harms, and the need for user-controlled technology over proprietary systems.
5.6Remembering Dave Täht
2025-04-01 • internet technology bloat dave täht tribute album
A heartfelt tribute to Dave Täht, celebrating his contributions to the internet and the personal bond shared with the author over a decade of collaboration.
A new wired setup for a wireless testbed is created to ensure consistent experimental results after a lab relocation, utilizing electrical attenuators and careful planning.
4.4Slow travel
2025-06-07 • reflection travel train rides slow movement
The author values the meditative and fulfilling experience of slow train travel over the stress and disorientation of flying.
3.6It's not dead, it's resting!
2023-04-20 • blogging technology career personal
After a four-year hiatus, the author announces their return to blogging, reflecting on their PhD completion and work as a kernel engineer at Red Hat.
0Nearing the end: Thesis defence
2018-11-21 •
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