.. назва: Інтерактивна діаграма кінцевого автомата TCP
.. slug: tcp-state-machine
.. дата: 2026-03-27 12:00:00 UTC
.. теги: мережа, tcp, rfc793, кінцевий автомат, калькулятор, інструмент
.. категорія: Калькулятори
.. посилання:
.. опис: діаграма кінцевого автомата TCP, яка охоплює всі стани RFC 793. Показує події ініціювання, обмін пакетами, таймери та підказки щодо діагностики типових застряглих станів.
.. тип: текст
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<div class="calc-container">
<div class="calc-header">
<h2>Інтерактивна діаграма кінцевого автомата TCP</h2>
<p>Клацніть будь-який вузол стану, щоб переглянути події запуску, обмін пакетами, таймери та підказки щодо діагностики застряглих станів.</p>
<div class="legend">
<div class="legend-item"><div class="legend-dot" style="background:#28a745"></div>Початковий/кінцевий стани</div>
<div class="legend-item"><div class="legend-dot" style="background:#4CAF50"></div>Нормальні стани</div>
<div class="legend-item"><div class="legend-dot" style="background:#dc3545"></div>TIME_WAIT / зависло</div>
<div class="legend-item"><div class="legend-dot" style="background:#f7971e"></div>Закриття станів</div>
</div>
</div>
<div class="result-section">
<div class="section-header">Діаграма стану</div>
<div class="section-content" style="padding:12px">
<div id="cy"></div>
</div>
</div>
<div class="result-section" id="detailPanel">
<div class="section-header">Деталі штату</div>
<div class="section-content" id="detailContent">
<p style="color:#999">Натисніть вузол стану вище, щоб переглянути деталі.</p>
</div>
</div>
</div>
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        desc:'Server is waiting for an incoming connection request.',
        diagnosis:'Stuck LISTEN: Port not open. Check: ss -lntp | grep &lt;port&gt;' },
    SYN_SENT:   { color:'#0f3460', event:'Client calls connect(). SYN sent.',
        packet:'Sends SYN', timer:'SYN-timeout (~75s)',
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        diagnosis:'Many SYN_RCVD: SYN flood / DDoS. Enable tcp_syncookies: sysctl -w net.ipv4.tcp_syncookies=1' },
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        diagnosis:'Many TIME_WAIT: Normal under high connection rate. Mitigate: tcp_tw_reuse=1, reduce tcp_fin_timeout, use persistent connections, or load balance across more ports.' },
};

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