https://besterry.com/tags/kernel/Recent content in Kernel on Besterry — Linux & DevOps NotesHugoen-usSat, 10 Feb 2024 00:00:00 +0000https://besterry.com/posts/linux-networking-deep-dive/Sat, 10 Feb 2024 00:00:00 +0000https://besterry.com/posts/linux-networking-deep-dive/<p>Every time a packet leaves your Linux machine, it travels through a surprisingly long sequence of stages. Understanding this path helps enormously when debugging network issues.</p> <h2 id="the-socket-layer">The socket layer</h2> <p>When your application calls <code>send()</code> or <code>write()</code> on a socket, the kernel&rsquo;s socket layer takes over. For a TCP socket this means handing the data to <code>tcp_sendmsg()</code>, which in turn enqueues it into the socket&rsquo;s send buffer.</p> <p>You can observe the send queue depth with <code>ss -tipm</code>:</p>