.. العنوان: الرسم التخطيطي التفاعلي لآلة حالة TCP
.. سبيكة: tcp-state-machine
.. التاريخ: 2026-03-27 12:00:00 بالتوقيت العالمي
.. العلامات: الشبكات، برنامج التعاون الفني، RFC793، آلة الدولة، آلة حاسبة، أداة
.. الفئة: الآلات الحاسبة
.. الرابط :
.. الوصف: رسم تخطيطي لآلة حالة TCP قابل للنقر يغطي جميع حالات RFC 793. يعرض الأحداث المحفزة والحزم المتبادلة والمؤقتات ونصائح التشخيص لحالات التوقف الشائعة.
.. النوع: نص
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<div class="calc-container">
<div class="calc-header">
<h2>الرسم البياني التفاعلي لآلة حالة TCP</h2>
<p>انقر فوق أي عقدة حالة لرؤية أحداث التشغيل والحزم المتبادلة والمؤقتات ونصائح تشخيص الحالة المتوقفة.</p>
<div class="legend">
<div class="legend-item"><div class="legend-dot" style="background:#28a745"></div>حالات البداية/النهاية</div>
<div class="legend-item"><div class="legend-dot" style="background:#4CAF50"></div>الدول العادية</div>
<div class="legend-item"><div class="legend-dot" style="background:#dc3545"></div>TIME_WAIT / عالق</div>
<div class="legend-item"><div class="legend-dot" style="background:#f7971e"></div>حالات الإغلاق</div>
</div>
</div>
<div class="result-section">
<div class="section-header">مخطط الدولة</div>
<div class="section-content" style="padding:12px">
<div id="cy"></div>
</div>
</div>
<div class="result-section" id="detailPanel">
<div class="section-header">تفاصيل الدولة</div>
<div class="section-content" id="detailContent">
<p style="color:#999">انقر فوق عقدة الحالة أعلاه لرؤية التفاصيل.</p>
</div>
</div>
</div>
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        packet:'Receives SYN', timer:'—',
        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)',
        desc:'Client sent SYN, waiting for SYN-ACK.',
        diagnosis:'Stuck SYN_SENT: Firewall dropping SYN, or server not listening. Check MTU/PMTUD if SYN goes out but SYN-ACK never arrives.' },
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        packet:'Receives SYN, sends SYN-ACK', timer:'SYN-backlog timer',
        desc:'Server received SYN, replied with SYN-ACK, waiting for ACK (3-way handshake).',
        diagnosis:'Many SYN_RCVD: SYN flood / DDoS. Enable tcp_syncookies: sysctl -w net.ipv4.tcp_syncookies=1' },
    ESTABLISHED:{ color:'#28a745', event:'ACK received. Connection open.',
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        packet:'Received ACK for FIN', timer:'tcp_fin_timeout (60s default)',
        desc:'ACK received for FIN, waiting for remote FIN to complete half-close.',
        diagnosis:'Stuck FIN_WAIT_2: Remote app never called close(). Reduce tcp_fin_timeout. ss -ant state fin-wait-2' },
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        packet:'Receives FIN, sends ACK', timer:'—',
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    CLOSING:    { color:'#f7971e', event:'Both sides send FIN simultaneously.',
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        desc:'Waiting 2×MSL to ensure remote received the final ACK, and to prevent old segments from being accepted by a new connection.',
        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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];

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