Topical Takes
Short, opinionated posts on eBPF, Linux internals, and the tools we all run in production.
How Do I Prove a Network Problem Isn't on Our Side? (2026)
Every cross-team incident reaches the same deadlock: two sides with dashboards that disagree and no shared evidence. The packets settle it. Here is what actually counts as proof on Linux, how to show which side closed the connection first, and how to capture what a third-party endpoint really sent back.
Who Is Resetting My TCP Connections on Linux? (2026)
Every guide to connection reset by peer ends at the same place: run tcpdump and read the source address of the RST. That gives you an IP, not a cause. Here is how to find which process owned the reset socket on Linux, tell a peer reset apart from a kernel one, and watch resets live without a capture file.
Why Is My TLS Handshake Failing on Linux? (2026)
A TLS handshake fails before your application logs anything useful, which is why the error you get is generic and the cause is not. The negotiation itself is cleartext on the wire, including the hostname your client sent and the alert that ended it. Here is how to read both on Linux without the private key and without restarting the process.