Unicast, multicast y broadcast. Curso de redes desde 0 | Cap 19 |

NASeros
19 Feb 202412:00

Summary

TLDREl guion del video explica por qué es crucial tener redes pequeñas y segmentadas. Se discuten los tipos de transmisión de datos: unicast, multicast y broadcast, y cómo estos afectan la red local. Se enfatiza la importancia de entender estos conceptos para entender VLANs, que se explorarán en un próximo video. Además, se ilustra cómo el tráfico de broadcast puede saturar la red y la necesidad de segmentar la red para reducir el tráfico de broadcast, mejorando el rendimiento y la eficiencia de la red.

Takeaways

  • 😀 Es importante tener redes pequeñas y segmentadas para una mejor gestión.
  • 🖥️ Las redes actuales tienen muchos dispositivos conectados, desde teléfonos hasta refrigeradores.
  • 📡 Los tipos de transmisión en redes incluyen unicast, multicast y broadcast.
  • ✉️ Unicast envía paquetes de información a un solo destinatario.
  • 🔄 Broadcast envía paquetes a todos los dispositivos en la red, lo que puede saturarla.
  • 📢 Multicast envía información solo a los dispositivos suscritos a un grupo específico.
  • 📊 El tráfico broadcast puede ocupar mucho ancho de banda y saturar la red.
  • 🔍 Wireshark es una herramienta útil para analizar el tráfico de red y ver la cantidad de tráfico broadcast.
  • 📶 Dividir la red en dominios de broadcast más pequeños ayuda a reducir la congestión.
  • 🖧 Las VLANs permiten segmentar la red de forma eficiente utilizando un solo switch.

Q & A

  • ¿Por qué es importante tener redes pequeñas y segmentadas?

    -Las redes pequeñas y segmentadas son importantes porque ayudan a gestionar el tráfico de datos de manera más eficiente, mejoran la seguridad y reducen la sobrecarga de tráfico en la red, especialmente en grandes redes domésticas con múltiples dispositivos conectados.

  • ¿Qué tipos de transmisión de datos se mencionan en el guion?

    -El guion menciona tres tipos de transmisión de datos: unicast, multicast y broadcast.

  • ¿Qué es unicast y cómo funciona?

    -Unicast es una conexión de uno a uno en la que la información se envía desde un dispositivo a otro específico. Es como enviar una carta con una dirección de destino única, y solo ese destinatario recibe el paquete.

  • ¿Cómo se describe el broadcast en el guion?

    -El broadcast es el proceso de enviar un paquete de datos a todos los dispositivos en la red, donde cada dispositivo recibe el paquete, lo revisa y si no es para él, lo descarta.

  • ¿Qué es DHCP y cómo se relaciona con el broadcast?

    -DHCP (Protocolo de Configuración de Host Dinámico) es un servicio que asigna direcciones IP a los dispositivos en una red. Se relaciona con el broadcast porque un dispositivo DHCP busca el servidor DHCP enviando una solicitud de broadcast que todos los dispositivos reciben y el servidor DHCP responde únicamente al dispositivo solicitante.

  • ¿Qué es multicast y cómo difiere de unicast y broadcast?

    -Multicast es una forma de transmisión de datos donde el paquete se envía a un grupo de hosts que se han suscrito para recibir esa información. Es diferente a unicast, que es la transmisión a un solo destinatario, y a broadcast, que envía el paquete a todos los dispositivos en la red.

  • ¿Qué problema puede causar el tráfico de broadcast en una red?

    -El tráfico de broadcast puede causar problemas como la saturación de la red y la disminución del ancho de banda disponible, además de que los dispositivos tienen que invertir recursos en comprobar si el paquete es para ellos, lo cual puede ser ineficiente.

  • ¿Cómo se puede reducir el tráfico de broadcast en una red grande?

    -Se puede reducir el tráfico de broadcast segmentando la red en dominios de broadcast más pequeños, utilizando dispositivos como switches y VLANs para dividir la red en segmentos más manejables.

  • ¿Qué son los VLANs y cómo ayudan a segmentar una red?

    -Los VLANs (Virtual Local Area Networks) son redes virtuales dentro de una red física que permiten aislamiento y segmentación lógica de la red. Ayudan a reducir la cantidad de tráfico de broadcast al limitar el alcance de los paquetes a un grupo específico de dispositivos dentro de la VLAN.

  • ¿Qué es Wireshark y cómo se utiliza en el guion para demostrar el tráfico de red?

    -Wireshark es una herramienta de análisis de redes que captura y muestra el tráfico de red. En el guion, se utiliza para ilustrar la cantidad de tráfico de broadcast en una red doméstica y cómo este puede ser significativo en un corto período de tiempo.

  • ¿Qué analogía se utiliza en el guion para explicar el concepto de broadcast en una red?

    -Se utiliza la analogía de una boda con muchos invitados en un restaurante. Cuando alguien grita preguntando dónde sentarse, todos los demás se detienen y miran, lo que es similar a cómo los dispositivos en una red responden a un paquete de broadcast.

Outlines

00:00

🌐 Importancia de las redes pequeñas y segmentadas

El primer párrafo explica la importancia de tener redes pequeñas y segmentadas, destacando los problemas que pueden surgir en redes grandes, especialmente en el hogar, donde dispositivos como teléfonos, tabletas, televisores, altavoces inteligentes y más están conectados. Se menciona que estas redes modernas difieren de las que teníamos hace 15 o 20 años y que es fundamental entender estos conceptos para comprender mejor los VLANs, que se explorarán en un próximo video. Además, se describe el proceso de envío de información en forma de paquetes, con direcciones de destino específicas, y se introducen los conceptos de unicast, multicast y broadcast como formas de transmisión de datos en la capa de enlace de datos (nivel 2).

05:02

📦 Unicast, Multicast y Broadcast en redes

Este párrafo profundiza en los diferentes métodos de transmisión de datos en una red: unicast, multicast y broadcast. El unicast, que implica la transmisión de información de un ordenador a otro de manera individual, se ilustra con un ejemplo de red típica que incluye un router, un switch, varias computadoras, una cámara de vigilancia, un servidor, un punto de acceso WiFi y varios teléfonos. Se describe cómo funciona el broadcast, donde un paquete enviado llega a todos los dispositivos de la red, y se menciona un caso específico de DHCP como ejemplo de uso de broadcast. También se introduce el multicast, que solo envía información a los hosts que desean recibirla y están suscritos a un grupo multicast específico.

10:04

🚧 Problemas del tráfico de broadcast y la solución de segmentación de redes

El tercer párrafo aborda los problemas que puede causar un tráfico de broadcast intenso, como la saturación de la red y la necesidad de que los dispositivos revisen constantemente si los paquetes son para ellos. Se utiliza un ejemplo de Wireshark para mostrar la cantidad de tráfico de broadcast en una red doméstica. Luego, se hace una analogía con una boda para ilustrar el concepto de unicast, multicast y broadcast. Finalmente, el párrafo sugiere la segmentación de la red en grupos más pequeños para reducir el tráfico de broadcast, presentando la idea de utilizar VLANs, que se explicarán en detalle en el siguiente video.

Mindmap

Keywords

💡Redes segmentadas

Las redes segmentadas son una práctica clave en la informática para dividir una red más grande en múltiples sub-redes más pequeñas. En el video, se discute la importancia de tener redes pequeñas y segmentadas para mejorar la gestión y la seguridad. Por ejemplo, se menciona que al segmentar una red, se reduce el tráfico de difusión y se mejora la eficiencia al evitar que los paquetes lleguen a todos los dispositivos innecesariamente.

💡Difusión (Broadcast)

La difusión es un tipo de transmisión de datos en una red que permite enviar un paquete a todos los dispositivos en la red. En el script, se destaca cómo la difusión puede saturar la red y generar problemas de rendimiento, especialmente en redes grandes. Se ilustra con el ejemplo de DHCP, donde un equipo solicita su configuración de red a todos los dispositivos de la red mediante un paquete de difusión.

💡Unicast

Unicast se refiere a la transmisión de datos de un solo emisor a un solo receptor. Es una conexión uno a uno y es fundamental para la comunicación entre dispositivos en una red. En el video, se describe cómo funciona el unicast con un ejemplo de cómo un ordenador envía datos a otro ordenador específico en la red.

💡Multicast

Multicast es una forma de transmisión de datos donde un emisor envía información a un grupo específico de receptores en lugar de a todos en la red. Se menciona en el script como una forma más eficiente de comunicación que difusión, ya que solo los dispositivos interesados en el grupo reciben los paquetes.

💡VLAN (Virtual Local Area Network)

VLAN es una tecnología que permite dividir una red en sub-redes lógicas a nivel de enlace, sin la necesidad de hardware adicional. En el video, se anticipa que en el próximo video se explicará cómo se crean y son importantes los VLANs para segmentar redes y mejorar la organización y seguridad.

💡Análisis de tráfico de red

El análisis de tráfico de red es el proceso de examinar los datos que viajan a través de una red. En el script, se utiliza Wireshark, una herramienta de análisis de red, para demostrar cuánto tráfico de difusión hay en una red doméstica en tan solo unos segundos, mostrando la cantidad de paquetes de difusión.

💡Flooding

Flooding es el proceso mediante el cual un enrutador o conmutador envía un paquete a todos los puertos en una red, excepto el puerto de origen. En el contexto del video, se describe cómo el flooding se usa en la difusión para replicar un paquete a todos los dispositivos de la red.

💡Conexión

En el video, la conexión se refiere a la forma en que los dispositivos se comunican en una red. Se menciona en el contexto de unicast, donde hay una conexión uno a uno entre dos dispositivos, y en el de multicast, donde un emisor envía datos a un grupo específico de receptores.

💡Enrutador

Un enrutador es un dispositivo de red que conecta dos o más redes y dirige el tráfico entre ellas. En el script, se describe cómo un enrutador puede tener un servidor DHCP que responde a las solicitudes de configuración de red de un dispositivo que envía una solicitud de difusión.

💡Switch

Un switch es un dispositivo de red que conecta múltiples dispositivos y permite la comunicación entre ellos. En el video, se discute cómo el uso de switches puede ayudar a segmentar una red en varias sub-redes para reducir el tamaño del dominio de difusión y mejorar la eficiencia de la red.

💡Analogía

El video utiliza analogías para explicar conceptos técnicos, como la comparación de una red con una boda, donde los asistentes representan los dispositivos de la red y las interacciones entre ellos se asemejan a los diferentes tipos de transmisión de datos (unicast, multicast, broadcast).

Highlights

La importancia de tener redes pequeñas y segmentadas.

Explicación de los tipos de transmisión en una red local.

Los problemas en redes grandes, especialmente en el hogar.

El crecimiento de las redes en los últimos 15-20 años.

La necesidad de entender conceptos básicos antes de aprender sobre VLANs.

Cómo se envía información en forma de paquetes en una red.

La diferencia entre unicast, multicast y broadcast.

Unicast: transmisión de información de uno a uno.

Broadcast: envío de paquetes a todos los dispositivos de la red.

El caso de uso de Broadcast en DHCP.

Cómo funciona el multicast, solo para hosts suscritos a un grupo.

El problema de tráfico de broadcast y su impacto en la red.

La utilización de Wireshark para analizar el tráfico de broadcast en una red doméstica.

Análisis de la cantidad de tráfico broadcast en pocos segundos.

Analogía del uso de broadcast en una boda con una red.

La solución de segmentar la red para reducir el tráfico de broadcast.

Introducción a VLANs como una forma de segmentar redes sin necesidad de múltiples switches.

VLANs permiten crear múltiples dominios de broadcast en un solo switch.

Sesión de Q&A y reflexión sobre los conceptos aprendidos.

Transcripts

play00:00

Today I'm going to explain why it is very important to have small and segmented networks. to have small and segmented networks I'm going to

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explain what are the types of broadcasting is something very important within a important within a local network and many times

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the problems that we have in a network come especially if the network is a little bit of a

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and keep in mind that nowadays a lot of people have large people have large networks even if it's

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at the home level Why very simple Because today networks have grown a lot because

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today we have phones tablets televisions smart speakers plugs light bulbs even

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the fridge is connected and makes today's networks nothing to do with today's networks have nothing to do with today's networks.

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that we had 15 or 20 years ago and it is also very important that we understand these concepts. important that we understand these concepts.

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Because in the next video I'm going to explain what VLANs are. How do you segment through VLANs?

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How important they are and the concepts that I'm going to I'm going to explain today are going to be necessary for us to understand

play00:46

well what a VLAN is in the next video so if you're interested in learning all of this, stay tuned. you're interested in learning all of this stay tuned.

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we start when we send information on a network as we know network as we already know what we do is we send it out.

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in the form of packets we chunk the information we divide it into smaller packets and when we

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we send that packet in the packet we write the destination address to where we want it to go

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that packet arrives that is explained in the course on networking from scratch here it is explained here

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it's in a series of videos I'm making explaining how networks actually work

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this video is also going to be included in there and what it's important it's important that that address

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destination we can say that it arrives at a specific destination or that it arrives at destination or we can say that it arrives at several destinations i.e.

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we can send the package to a single recipient or to multiple recipients that's what's known as the

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as unicast, multicast and broadcast we are going to see how it works let's see what the differences are

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Because it is very important because depending on how we send this packet or another one, it will behave in the following way

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one way or the other, first of all I have to say that what I am going to explain I have to say that what I am going to explain now is for

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the link layer level for level two you already know that there are you know that there are several levels for the levels of

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OSI is explaining in the course of networking and everything this is at the link level at the layer two level at

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first of all we have unicast and what does it consist of? Well it's basically what we all know as

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sending information from one computer to another or from one computer to another would be a one-to-one connection.

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in such a way that we from a computer from an interface what we do is we send a frame to a computer.

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because when we're talking about level two it's not called a packet it's called a frame. it's not called a packet it's called a frame.

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same way we send a packet we send a frame with only one a single recipient so that packet is only

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has a single destination in the first place let's let's see how the unicast works here we have

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a typical network where we have a router a switch a switch several computers one video surveillance camera

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a server a wifi access point to which several phones are connected a laptop computer several phones a laptop

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so that would be a typical configuration and let's see how unicast works. let's see how unicast works we have for example

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computer 1 that wants to communicate with computer 4 and that would be unicast computer 4 and that would be unicast how does it De

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this way it would send a packet with the information I symbolize it as if it were an envelope as if

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it would be a letter and the computer sends it to the it goes to the switch and then the switch what is the

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it sends it only and exclusively to computer 4 because it is the to computer 4 because it's the recipient of

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that packet then we would have the broadcast. What the broadcast consists of is everything

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opposite of the unicast, that is to say we send a packet a packet AND instead of having a single recipient

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has all the computers on the network, all the interfaces on the network or all the interfaces on the network or all the nodes on the network.

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network however we want to say it we send a packet and a packet and all the computers that are on that

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network will receive it, now let's see how the broadcast works. broadcast would work we have the same network

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and how it would work would work as follows computer one sends an information

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but not to computer 4 as it did in unicast it would send it to sends it to everyone in this way it sends the information

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or the packet to the switch and the switch what does it do? it sends it by flooding it to all of the computers

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that's on the network without distinction the switch replicates the information to all the computers and now we go

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let's look at a specific case of broadcast as it would be for example, DHCP, for example imagine for example

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in the network we have that the computer 3 is that computer is configured through

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DHCP and it's turned on We've already turned it on and what does the computer do as it doesn't know what

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IP has it doesn't know what network it belongs to it doesn't know anything what does it do ask who to who all how

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sends a packet over the broadcast sends a packet over the broadcast sends a packet over the broadcast sends a packet over the broadcast receives it And what does the switch do It replicates it

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everyone the computer 3 is asking Hey where's the DHCP server who am what IP

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I have to set What is the data that I have to set up? I have to set all the computers receive

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the same information they receive that packet but as they are not the DHCP server the computers

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the server the video surveillance camera the phones what do they do? telephones what they do they don't pay attention

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they discard the packet they discard the information and who does pay attention the router the router does

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case why Because Generally the DHCP server is on the router DHCP server is in the router and the router says okay

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as I already know where you are because in the packet it already it says as if we were saying the sender you told me

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where you are, what do I do I answer you giving you the data you need but to whom

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only to you it is sent only and exclusively to you already through like if we say unicast it sends it to you the

play05:13

information directly from the router to the computer 3 and computer 3 with that information is

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consists in the fact that the computers that want to receive that packet that packet that information are subscribed to a

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multicast group in such a way that when we send that information, only the hosts that want to receive it will receive it.

play05:40

that are subscribed to that group and now let's go to the multicast case. let's go to the multicast case and how would the

play05:44

multicast in the following way the computer one would send in this case the information but

play05:50

instead of being to one computer or to all the computers To whom to those who are subscribed to the multicast

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if team 2, 4 and 5 are subscribed I would send the information only to those teams. the information only to those teams, the rest of the teams would send the information only to those teams.

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teams would not receive the information now that we already know the type of transmission traffic

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that we have within a network that we have the unicast and the multicast and the broadcast.

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the problem The problem is in the broadcast like It's logical Why very simple Because it can

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be a rather important traffic can be a traffic that occupies a traffic that takes up a lot of bandwidth and saturates

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the network a little bit but then we also have another problem and that is that as we have seen in the

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case of DHCP, when a computer receives a broadcast packet broadcast packet arrives to a computer which is what happens that

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it has to check if the packet is for it or not. if it's not for it, it discards it. But what happens if

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he gets a lot of packages that he has to be all the time looking to see if it's for him or not.

play06:42

that you see the broadcast traffic inside a network. a network let's go to my computer we're going to use

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a program called Wireshark, which is a network network analyzer so we'll go to

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see how much traffic there is just inside my network my network on a home network we're going to look at the

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broadcast traffic that we have I open up Wireshark and here it is it's already started capturing all of the

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traffic and well I'm going to stop it now Okay, you've seen that it's been

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very few seconds and here's broadcast, broadcast, broadcast, broadcast, broadcas,t broadcast,

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broadcast we see that the source IP is displayed. destination IP is displayed in all source IP and destination IP.

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destination but however in broadcast does not appear source ip and then appears broadcast destination,

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broadcast is everything. the destination IP is not shown here you can see it and

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you have already seen that nothing in just a few seconds there is a lot of broadcast evidently if I pull

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upwards there is also a lot more broadcast here it is as we can see there's quite a lot of traffic

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broadcast and that's something that is quite common let's look at an analogy for example which would be the

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celebration of a wedding with a network why because it's something very similar imagine that we have

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a wedding with a lot of guests and we have a wedding celebration inside a restaurant and every single person in that

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restaurant every person in that celebration outside a team a team from a network what happens that in

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the unicast is very simple how would be the unicast we are inside the celebration inside the

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restaurant and two people who are talking one one to one in a conversation that would be unicast one to

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one What would be multicast ? Multicast would be when those diners there's typically a small group of people

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and as groups of people talking that group of people would be a multicast. people would be a multicast would be a part of the people

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that are talking to each other inside of that whole room full of diners and now we're going to

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let's see how the analogy with the case of the broadcast we imagine this room full of people

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people are talking to each other and all of a sudden a new diner comes in and they don't know where they are.

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that would be a very similar analogy to that of the DHCP what would happen that this person gets into the

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door and yells out where do I sit so everyone stops talking and turns around. stops talking turns around looks at him as if he is not

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goes with them continues his conversation and the metre the person in charge person in charge comes up to him and points out his

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site But what has happened that has already so soon interrupted everybody that was inside the

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the room because everybody stopped talking and turned around to see what turned around to see what she was saying.

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person who was shouting then another person comes in person comes along and would do the same thing so there would be

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a lot of interruptions then imagine that the typical thing at weddings somebody who picks up

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a drink and gives it to him with a teaspoon and says: "viva the bride and groom", and the people start shouting Viva los

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boyfriends. Imagine that they do that every other time. The more people we have, the more nodes there are.

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or the more computers there are within that network what is what's going to happen that we have more traffic

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broadcast and what is it that we can do very very simple if we have a very large network if

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we have a lot of computers and we have a very large broadcast domain very large broadcast domain what can we do

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segment the network into smaller networks divide the network into smaller networks into smaller networks make that broadcast domain

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broadcast domain is much smaller so that in each group in each group in each broadcast domain there are fewer

play10:04

computers so that there will be much less information circulating within that information circulating within that segment

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network or within that network group is as simple as that. as simple as that we're going to divide the network into

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smaller groups as we see here we have a single broadcast domain i.e. all

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the packets arrive to all the computers and what we can do very easily is split the network

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in several parts in this case we can divide it into two parts for example in two parts we place two switchers

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in such a way that half of the computers such as in this case the four computers

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first we place them connected to a switch And then the rest of the computers are connected to a switch

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to a second switch and it would look like this We would have a broadcast domain that

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would only be for these computers here and then we would have a second domain of

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broadcast as we can see here I have painted the lines in another color and the envelopes in another color.

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color because they are totally independent networks the broadcast packets of broadcast 1 never

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will be able to reach broadcast 2 and vice versa. so that we will have a domain of

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much, much smaller broadcast And you're going to tell me that's fine but this is a mess because now I had a

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switch and I have to place two switches, what can we do? we can do put a single switch like

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this way and this is where the famous VLANs come in. the famous VLANs come into play I would have one part of the switch with

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VLANs in such a way that it would have a broadcast domain that would a broadcast broadcast domain that

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would belong only to VLAN 1 and then you would have a second broadcast domain 2. a second broadcast domain 2 would have

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exactly the same configuration as before before, but with a single switch and this

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as we will see in the next video in addition to this has a lot of advantages. But I'll leave that to

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the next video we already know one more thing this is going to help us explain the VLANs will be at

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the next video and as I always say if you liked the video like the video give it a like share it with

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people that you think this can help you and we'll see you in the next see you in the next one. Best regards. Bye bye bye

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Related Tags
Redes PequeñasSegmentaciónTransmisión de DatosVLANsBroadcastMulticastUnicastAnálisis de RedWiresharkDHCPEducativo
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