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🌐 Conceptos básicos

[PC] --[Red LAN]-- [Switch] --[Router]--> 🌍 Internet

• LAN: Red local (casa, oficina).
• WLAN: LAN con Wi-Fi.
• WAN: Conexión entre varias LANs, como Internet.
• VLAN: LAN virtual separada lógicamente aunque esté en la misma red física.

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🧠 Modelo OSI vs TCP/IP

Modelo OSI (teórico)

[7] Aplicación
[6] Presentación
[5] Sesión
[4] Transporte
[3] Red
[2] Enlace de datos
[1] Física

Modelo TCP/IP (real)

[4] Aplicación
[3] Transporte
[2] Internet
[1] Acceso a red

• OSI: Más detallado, para entender procesos.
• TCP/IP: El que se usa en Internet.

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✉️ Proceso de envío de datos (simplificado)

[Usuario A]
   |
[Aplicación]  (HTTP, DNS, etc)
   ↓
[TCP/IP]      (Divide en paquetes)
   ↓
[Red]         (Switch y Router)
   ↓
[Usuario B]

Cada capa agrega su información (encabezados) → se encapsula el mensaje → se envía → se desencapsula en destino.

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🔀 Conmutación (Switch + MAC)

+--------+       +--------+       +--------+
|  PC A  | <---> | Switch | <---> |  PC B  |
+--------+       +--------+       +--------+
       MAC A       usa MACs       MAC B

El switch crea una tabla interna tipo:

Dirección MAC	Puerto
MAC A	1
MAC B	2

Así sabe hacia dónde reenviar paquetes.

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🛰️ Enrutamiento (Router + IP)

[Red A] --- [Router A] --- Internet --- [Router B] --- [Red B]
          ↑ Tabla de enrutamiento       ↓
          Usa IP + Máscara + Gateway para decidir

El router consulta su tabla:

Red destino	Gateway	Interfaz
192.168.1.0/24	0.0.0.0	Eth0
10.0.0.0/8	192.168.1.1	Eth1

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📬 Ejemplo de IP y máscara

Supón:

• IP: 192.168.1.10
• Máscara: 255.255.255.0

Eso indica que el host pertenece a la red 192.168.1.0, y si quiere hablar con una IP como 192.168.2.10, debe salir por la puerta de enlace (el router).

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🔑 Resumen de elementos clave

Concepto	Ejemplo	Explicación rápida
Dirección IP	192.168.1.10	Identifica un dispositivo en la red
Máscara de red	255.255.255.0	Define a qué red pertenece la IP
Puerta de enlace	192.168.1.1	IP del router para salir de la red local
Dirección MAC	A1:B2:C3:D4:E5:F6	Identifica de forma única una tarjeta de red
DNS	google.com → 142.250.64.78	Traduce nombres a direcciones IP

When recruiters review resumes, they spend only a few seconds on the first glance. Research shows that their eyes move across the page in the shape of the letter F: first, they read the top line, then scan down while focusing on the left side. This is the principle behind the F-Method – a resume formatting technique that helps highlight the most important details.

How to Use the F-Method?
1️. First horizontal section: Start with a clear heading – include your name, contact details, and the job title you’re applying for.
2️. Second horizontal section: Place key information at the top – a brief summary of your skills, achievements, and strengths.
3️. Vertical section on the left: Since this area gets the most attention, list your most important details here – work experience, education, and key skills.

This method makes resumes easier to read, highlights essential points, and increases your chances of getting noticed. Use the F-Method, and your resume won’t go unnoticed! 🚀

What is real? How do you define real? If you’re talking about what you can feel, what you can smell, what you can taste and see, then real is simply electrical signals interpreted by your brain.
This is the world that you know. The world as it was at the end of the twentieth century. It exists now only as part of a neural-interactive simulation that we call the Matrix. You’ve been living in a dream world.
This is the world as it exists today… Welcome… to the desert… of the real.
We have only bits and pieces of information but what we know for certain is that at some point in the early twenty-first century all of mankind was united in celebration. We marveled at our own magnificence as we gave birth to AI.

AI? You mean artificial intelligence?

A singular consciousness that spawned an entire race of machines. We don’t know who struck first, us or them. But we know that it was us that scorched the sky. At the time they were dependent on solar power and it was believed that they would be unable to survive without an energy source as abundant as the sun. Throughout human history, we have been dependent on machines to survive. Fate, it seems, is not without a sense of irony. The human body generates more bio-electricity than a 120-volt battery and over 25,000 BTUs of body heat. Combined with a form of fusion, the machines have found all the energy they would ever need. There are fields, endless fields, where human beings are no longer born. We are grown. For the longest time I wouldn’t believe it, and then I saw the fields with my own eyes. Watch them liquefy the dead so they could be fed intravenously to the living. And standing there, facing the pure horrifying precision, I came to realize the obviousness of the truth.
What is the Matrix?
Control.
The Matrix is a computer generated dream world built to keep us under control in order to change a human being into battery.

• Jack Ma

“Today is difficult, tomorrow is much more difficult, but the day after tomorrow is beautiful. Most people die tomorrow evening.”