Hop to hop networking and End to end problem! - Please help!

[Maddog81]

Hi,
I have recently started working through basic IT support requirements, and basic networking. I want to change career basically - I won't bore you with details.
There is a very good guy on YouTube who explains these things v well, but one thing is tripping me up........do you need hop to hop networking AND end to end? Don't they both just 'want' to achieve the same thing. I understand each has different headers etc, so I figure you need both to move data from X to Y. OR are they seperate entities and can exist and function independently from one another? If you look at hop to hop, is it not just achieving an end to end function, by moving data through routers? If it were possible to JUST do end to end, from one machine straight to another - why bother with hop to hop, involving routers etc? OR, are both required? - One to 'carry' and IP and one to 'carry' MAC address etc?
 
 
Can end to end function without routers (like those implemented with hop to hop)? I hope I'm explaining it ok?
 
Thank-you for reading,
 
Matthew

[deanwebb]

The answer is that yes, we do both. If all we had was one switch, everything would be end-to-end and no more. But because we can't connect everything to one switch and because we don't necessarily want all traffic in an organization going to every other endpoint in the organization, we have multiple switches with multiple subnets to control traffic. And even if we did want that, the fact that electrical signals only travel so far before they need to be repeated means that for network traffic to span distances such as across a large campus or between cities or nations, we will need multiple devices to carry the signal, each acting as hops.

To get traffic from one subnet to another, we need to know which route to take. Because the route will traverse multiple devices, we will need to determine the hops that will collectively form the end-to-end route. When we consider the billions of devices connected to networks with Internet access, we need to have methods of summarizing how traffic moves locally, to indicate if the traffic will stay in our organizational networks or go out across the Internet.

[icecream-guy]

in the end-to-end scenario, this is kind of what a VPN does,  creates a tunnel between 2 endpoints, although to get there, it does go hop by hop, but it's just that the path is transparent, and the network engineer would never see the real hop by hop path (e.g. in a traceroute).