Question

basic networking question.

Let me draw the diagram first.

Answer 1

https://i.imgur.com/xBswJVk.jpg

Answer 2

i'm also having trouble differentiating a switch and a router. i've literally never seen a LAN Switch that connects all the local users on a network. i thought the router itself has those ports to connect local users together.

Answer 3

the first thing that bob's device will do is to check if Sarah's device is on the same subnet as itself
To do this bob's device will perform a some boolean math operations using the & operator
In this case they're both on the same subnet so bob's device has no need to send the packet to the default gateway
The next step is for bob's device is to get Sarah's device's MAC address, it'll check it's ARP cache to see if it already has the answer
If it doesn't have her MAC address it'll send an ARP packet on the network requesting the MAC address for 172.10.1.30, the ARP packet is a broadcast packet so all computers in the subnet will receive the packet but Sarah's device will reply to that packet cuz it has her IP on it.
Now that bob's device has Sarah's MAC address it'll simply send out a packet directly to Sarah's device
When Sarah's device receives this packet it'll see that it has her MAC address on it and therefore it'll bring it up into it's operating system and process it

Answer 4

yes but what does the subnetwork mask represents in this particular scenario ?

Answer 5

like what exactly is it designed to do? what's its function?

Answer 6

Also, all the interactions between users and network that happen, are they TCP/IP or UDP? or is that for only WAN ?

Answer 7

also, does a switch has its own IP and MAC? for instance this switch. https://ccimg.canadacomputers.com/Products/600x600/333/417/34280/38810.jpg

Answer 8

Bob's IP: 172.10.1.30
in binary: 10101100 00001010 00000001 00011110

Subnet mask:- 255.255.255.0
convert it into binary form : 11111111 11111111 11111111 00000000

so the Subnet mask is a 32 bit number: a string of 1s followed by a string of 0s.

In this example the first 24 bits of the IP address are designated as the network address (because there are 24 1s in the subnet mask) and the last 8 bits are for the host/the individual computers.

Answer 9

What do we need subnet for? what is its function?

well we need to assign an identification number to each device but
- we have limited amount of memory
- we don't know how big the networks that make up the internet are gonna be

So we break up the IP into two parts so one part is for the network and the other part is used to identify the host
we can't break up the IP from just anywhere because networks are different sizes

for example if you break it up in the middle you'll have 16 bits for the network and 16 bits for the hosts, that means you can have 65,636 different networks with each having 65,636 hosts/computers. But what if you needed only 20 hosts? There'll be a lot of wastage if you just break it from anywhere.

This is why we need Subnet. It provides us a way to dynamically change the number or the size of networks that can connect to the internet.

Answer 10

Bob's IP in binary: 10101100 00001010 00000001 00011110
Subnet : 11111111 11111111 11111111 00000000
_______________________________________

You can find the network IP by doing an & operation above
Network IP: 10101100 00001010 00000001 00000000 = 172.10.1.0

number of hosts = 00011110 = 30

Answer 11

\(\color{#0cbb34}{\text{Originally Posted by}}\) @Ballery1
Also, all the interactions between users and network that happen, are they TCP/IP or UDP? or is that for only WAN ?
\(\color{#0cbb34}{\text{End of Quote}}\)
It depends upon the type of application
Most applications use TCP/IP because there's no data loss but there are some applications which use UDP as well like video streaming

Answer 12

\(\color{#0cbb34}{\text{Originally Posted by}}\) @Ballery1
also, does a switch has its own IP and MAC? for instance this switch. https://ccimg.canadacomputers.com/Products/600x600/333/417/34280/38810.jpg
\(\color{#0cbb34}{\text{End of Quote}}\)
It depends upon the type of switch. Managed switches have their own IP but unmanaged one don't.

Answer 13

\(\color{#0cbb34}{\text{Originally Posted by}}\) @Ballery1
i'm also having trouble differentiating a switch and a router. i've literally never seen a LAN Switch that connects all the local users on a network. i thought the router itself has those ports to connect local users together.
\(\color{#0cbb34}{\text{End of Quote}}\)
Consider you wanna connect your computers to the router through ethernet and there are like 100 comupters. You'll only be able to connect like 4-5 computers because you'll run out of ports. When this happens you'd wanna use a switch, you can connect a switch to the routers and then connect your computers to the switch.

Answer 14

Just want to confirm one quick thing. So i have two scenarios first one involves sending traffic from my host to multiple hosts within a private LAN and the other one involves sending traffic to multiple hosts via WAN. To make things more precise, let's say i want to send multiple word docs to multiple users via LAN and WAN. My question is, will it follow the TCP/IP procedure and do three way hands shake to fully verify that the files have been transferred? Thanks :)

Answer 15

Also, if i wanted to make a LAN for home and personal use, do i need to have internet access to be able to connect with other hosts on the same network in my house? The reason i'm asking is because the basic networking revolves around switches and routers so i was wondering what if i have a switch and no router/internet, can i still be able to communicate with other ppl in my house? Thanks :)

Answer 16

Also can you have two routers within a private LAN that share the same ip and mac address and subnet mask?

Answer 17

Also, when i try to access information on a network that is on the other side of russia, and let's say the distance from my location to the server in russia is some 900 routers away. So when my packet hops from router to router, it'll surely get on different network providers routers. My question is, can the network provider see what info is being sent through their network? because when a packet hops from router to router, only the port and source#, source and destination IP addresses stay the same. The Source and Destination Mac addresses changes as the packet hops from router to router. So it is possible to have info breach via router? or at least track the path of a path via a router? Thanks :)

Answer 18

track the path of a packet via router*