Comments by "Javier Flores" (@JJFlores197) on "REAL LIFE example!! (TCP/IP and OSI layers) // FREE CCNA // EP 4" video.

  1. A pure router is only used for routing. It doesn't have any switching capabilities. Most typical home routers have a switch built in, but enterprise and business-level routers usually only have a few network ports (LAN and WAN and maybe some failover/aux ports). That's why they plug in a switch after the router.
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  2. Most routers have more than 1 interface. Each interface has its own MAC address. Typically, you have a "LAN" interface. This interface is what is connected to the switch. The "WAN" interface is what connects to the modem. So when you send a packet from your PC to a website, the packet goes from your PC, to the switch and into the router's LAN port. The router then changes the destination MAC address from its LAN interface to its WAN interface. That's why you see that in the video.
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  3. I strongly suggest watching other videos. NWC is a good presenter but he doesn't go in-depth. You won't learn how to setup a Cisco router or switch just with these videos. Jeremey's IT Lab has a really good CCNA course. He may not be as enthusiastic as NWC, but his course is actually complete.
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  4.  @cf6634  Routers have multiple interfaces. Typically, you have a LAN interface that sends/receives traffic to/from the network and you have a WAN interface which sends/receives traffic to/from the internet. Each interface has a MAC addresses. When the packet is to be sent through the WAN interface, the router adds the MAC address of its WAN interface in the Layer 2 frame because that is the source interface.
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  5. He doesn't explain it well. Routers usually have multiple physical interfaces. Each interface has its own MAC address. So when Johnny's laptop sends the data to the router, it arrives at the router's LAN interface. Internally, the router forwards this packet to the WAN interface (that connects to the ISP modem) and this interface has its own MAC address.
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  6. Yep. I find that amazing as well. A few years ago, I started playing around with creating my own VPN server at home. My family and I went to Mexico during the summer in 2019 and I thought it was awesome how I was able to remote into my home network from my grandparent's home over the VPN connection 2000 miles away!
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  7. Good luck. There's a lot more to learn for the CCNA than what he goes over. This series is extremely incomplete.
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  8.  @mateuszwasielewski7193  It would first require a hacker to get into the router. Then, the router has to support those features. It would be extremely unlikely that it happens.
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  9. In a real setup the web server would be at a data center. The switch would be in between the router and the computers and servers. This illustration in the video is just showing a simple network setup. In the real world, your router is not directly connected to another router physically.
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  10. What kind of trouble?
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  11. He doesn't explain it well. Routers usually have multiple physical interfaces. Each interface has its own MAC address. So when Johnny's laptop sends the data to the router, it arrives at the router's LAN interface. Internally, the router forwards this packet to the WAN interface (that connects to the ISP modem) and this interface has its own MAC address.
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  12. Are you sending any HTTP/HTTPs traffic in any of your computers/devices in packet tracer? If not, you won't see any traffic.
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  13. My suggestion is to use other channels. This series as is is far from complete. There is very little CCNA-specific stuff. I would watch David Bombal or Jeremey's IT lab. They may not be as "exciting" as NWC, but they are much more complete.
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  14. What part of the video are you asking about?
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  15. The router doesn't care about the MAC address. It only cares about the IP address. Let's say you have PC 1 trying to talk to Web server 1 on some website. PC 1 doesn't know Web Server 1's MAC address. PC 1 sends the frame. In the destination MAC address, PC 1 puts the MAC address of the router in your network. In the destination IP address, it contains the servers' IP address. When the router receives the packet, it will then send the packet out its WAN interface out to the ISP's network which in turn they will route the packet until it gets to its destination.
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  16.  @Animeaddictfreak  Routers have at least 2 interfaces: LAN and WAN. When your PC sends a packet to the router, as I mentioned, the PC puts the MAC address of the router as the destination MAC address. The router receives this packet. Its internal process puts the MAC address of its (router) LAN port as the source MAC and puts the MAC address of its WAN port. As I said, routers don't directly work with MAC addresses. Router 1 doesn't care or know about the MAC address of Router 2's WAN port. The only thing the router needs is the IP address of the next destination.
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  17. ??? That doesn't make any sense in relation to this video.....
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  18. Not necessarily. Pinging, in computer networking, just sends an IP packet to a remote host to determine if said host is reachable. When you visit the website via web browser, there are more things going on behind the scenes in order to request the website and then download it along with the required assets.
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  19. The destination MAC address in the frame is FF:FF:FF:FF:FF (this is known as the broadcast MAC address). Yes you're correct in that the switch can't read IP addresses, but the frame has that broadcast address which causes the switch to send that frame to all devices plugged into it.
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  20. I have a co-worker who worked as a network admin years ago. He had his CCNA until it lapsed years ago. He also hated the wording of the questions. They're almost written to trick you. Sometimes the questions have different correct answers, but you have to select the "Cisco correct" answer.
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  21. Routers typically have 2 interfaces: LAN and WAN and they both have MAC addresses. When you send a packet from your PC to your router, it actually arrives at the LAN interface. Internally, the router sends that packet from LAN interface to the WAN interface which causes the MAC address to change from the LAN's interface to the WAN's interface.
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  22. If you're referring to 4:53, that's normal. You can make 2 distinct networks on a single router. That is what is called a subnet. I think he just showed it in this way for simplicity.
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  23. You have to create a Cisco Netacad or "Skills for All" account and then login with it. Its an annoying requirement IMO.
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  24. Routers typically 2 interfaces: A LAN and WAN. All interfaces have a MAC address.
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  25. What time in the video are you referring to?
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  26. LOL dude. Like dude, if you're going to watch a training on the CCNA, you really have to know switching. Yes, the vast majority of people have no Cisco switches in their home but you have to learn it for the CCNA.
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  27.  @carlitodidthat  He's going by the OSI model dude. Switches are layer 2 whereas routers are at layer 3. That's why he started with switches.
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  28. There's a scroll bar at the bottom. Scroll to the right to see the rest of the network.
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  29. It has 2 network interfaces.
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  30. Routers typically have at least 2 interfaces: one that is assigned to the internal network and one that is for WAN. They both have different MAC addresses. Its something I wish NWC would explain. He touts this is as a CCNA course, but there are many things that he has missed due to the series being incomplete. Something like this is a little detail, but it is important to know to truly understand what's going on in the network.
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  31. There are higher end routers that can operate at higher levels of the OSI model. They may do things like packet inspection or SSL decryption, etc. But they have to be specifically configured for that. That's typically only done in businesses or larger organizations for data protection.
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  32. It all works through the layers of the OSI model. The different layers get encapsulated. So when your PC sends a packet to a server (say a web request) that data is sent to the switch. The switch only cares about the L2 header which are the source and destination MAC addresses. It then forwards that frame to the router. The router receives this packet and looks at the L3 header (it also looks at the source MAC address).
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  33. Its the same thing as he shows in the video. That's the basis of how networking works. It gets more complex if you want to learn at the service provider level though.
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