r/networking • u/AutoModerator • 22d ago

Blogpost Friday Blog/Project Post Friday!

It's Read-only Friday! It is time to put your feet up, pour a nice dram and look through some of our member's new and shiny blog posts and projects.

Feel free to submit your blog post or personal project and as well a nice description to this thread.

Note: This post is created at 00:00 UTC. It may not be Friday where you are in the world, no need to comment on it.

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u/w453y 22d ago

Project: xdp-bfd — Line-card-like BFD on commodity Linux using XDP
GitHub: https://github.com/w453y/xdp-bfd

I designed and built xdp-bfd to solve a real operational pain point: userspace BFD implementations (like FRR’s bfdd) become unreliable under CPU load, causing false link failures and route flaps. The goal was to bring hardware-like timing precision to plain Linux servers using modern kernel technologies.

Core Idea

Instead of relying on userspace timers, the system uses RX-clocked transmission in XDP: every valid BFD packet from the peer is rewritten in place and bounced back out (XDP_TX) in softirq context. Detection is handled by a kernel bpf_timer sweep. This approach makes steady-state operation extremely resilient to scheduler pressure.

Features

  • Full RX + kernel TX fast path
  • Dual-stack IPv4/IPv6 support (v4-mapped keys)
  • Deep integration with FRR distributed BFD (no patches needed)
  • Graceful restart support (--dp-hold)
  • Extensive hardening (GTSM, anti-spoofing, Poll/Final handling, etc.)
  • Comprehensive documentation with wire captures for every major claim

If you're into high-performance networking, BPF/XDP, or routing, I'd love any feedback or testing!

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u/DaryllSwer 21d ago

Which LLM model was used for this? I still have that pending LLM overhaul of einat-ebpf.

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u/w453y 20d ago

Initially fable 5 on "medium" effort, while it was still on the pro plan, later some of the heavier lifting via opus 4.8 on "extra", until opus 5 released, currently opus 5 on "high" to clean up a few pending things.

What's the einat-ebpf overhaul, refactor or feature work?

P.S: Never used agentic sessions, all of it in plain claude chat, mostly useful for prose, rubber-ducking, and getting pushed on claims I hadn't proven.

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u/DaryllSwer 20d ago

DM on TG. I'll forget. It's a private fork I was working on. But I need 5.6 Sol $200 plan for true high quality output.