Welcome to this lecture.
Let's learn about some basics of networking in this lecture.
So first of all you can see we have these four modules that is available in these network.
And basically we have this client and server so they communicate with each other so that we get the
services like email and a webpage.
So there is this browser which is the client.
It make a request to the server which is connected to the network and it will this again.
The response is appears to the client web addresses are basically to the client to a browser.
So this is the first module and the next one is really important and it is IP addresses and the MAC
addresses it is how the device on the network can be found.
So if you want to send any information it is done with these two modules and it is IP addresses and
MAC addresses and particularly MAC address is the logical address in which the device can be found on
the network.
So based on this MAC addresses is just find a particular muslin.
So what we can see is the MAC addresses is only the particle or basically it is only the way so that
anyone who is doing illegal work can be traced out.
So if you want anonymity you have to try hard not to just get a leak of this MAC addresses and even
the IP addresses will see that in the letter where we cover how to remain anonymous it galley Linux
and you can see the third building block and it is about the network hops switches and the cable and
you know that is we have these connections in order to support the networking and it is a hardware building
block of any network.
And the next one is the router and a firewall and it is about to organize and control the flow of traffic
on the network.
So this router will just get the information and based on that information it will thus control the
flow of traffic on the network.
So now let's see how we can get the IP addresses and MAC addresses with the windows.
So first of all let me open this command prompt and if I just type IP config and if I hit enter you
are getting these connections so of Wi-Fi and it is with the LAN Adapter and you can see the two addresses
over here.
One is IP addresses which is the IP addresses of these missing and the next one is your MAC address.
So this MAC address is different on different computer so you'll have different MAC addresses and IP
addresses.
And based on this MAC addresses that information will be given to the particular computer correctly
and you can see the gateway right here.
So the first subnet of any IP addresses will be the gateway.
So you could see that we have the same network.
And the first subnet is your gateway which is default gateway.
So you can get this information with the help of IP config in the window.
Let's see under Linux.
So I have your colleague Linux and I'll just say I have config and if I hate it then you could see right
here we have the ether is in mac addresses and the IP addresses is not here because we have not activated
any device over here.
So we'll see that in the upcoming lecture.
But it is the way to see the IP addresses and the MAC addresses in the linux machine.
So back to here.
So you couldn't see that we have this data frame containing the header and the data so data is basically
the actual information in the bits.
And here is what we contain of these MAC addresses so we can clearly see that this header is composed
of these MAC addresses which means it has source MAC address and destination MAC address.
That means with the hidden parmesan you will deliver the information correctly to the particular machine.
That means this MAC addresses is a logical addresses with the domains where this data should be sent.
So you could see that we have these simplified it data frame so a data frame is composed of the header
which contains of these MAC addresses and other information with this data that need to be sent.
So you can see our models are made up of these four informations and that is Glanton server which are
the two most in physical magazine that are going to do the connection are the communication.
And one will just do the request and other will just give the response the next one is the IP addresses
and MAC addresses.
This will determine where the data or information should be sent within the network and you can see
the sort of suites and cables which is going to be less a network.
And next one is a router and firewall.
They will organize and control the flow of traffic within the network.
So let's go down and let's see this space over here.
We source this diagram and this diagram is very important diagram.
So let's assume that we have this public network and a private network.
So in the private network the first gateway will be your gateway default gateway or first subnet of
your network will be the default gateway.
So over here we have this machine that is connected to Wi-Fi network in each of these have these IP
addresses.
So these dot one refers to these IP addresses and last subnet over here and you could see that this
is going to deliver the information to the computer.
So to send an IP packet to the network device the sender of this router needs to know the IP address
of the destination device.
So if they don't know the destination device IP address it is not going to send any information.
So the IP address will be used to get the data packet to the final network segment.
So in order to deliver the packet to the final destination the MAC addresses of our destinies and computer
must be also known.
So the protocol should be use and that protocol is ERP protocol which stands for address resolution
protocol.
So where it is used is in Internet broadcast to query the N on the network.
So the query will be something like weeds nor do or which of these devices has the IP addresses or a
destination IP addresses and they will say send me that mac addresses.
So that will be the information that is done with the ad request.
So our request is done so as to get the MAC addresses so that information will be sent correctly to
that machine.
So in order to see that all the node will see that query that is the query that is done with the ADP
request but only the node or only the computer with that destination ip addresses replays other.
All will ignore that masses and only the machine that has the particular MAC addresses will replay.
And in that way there will be the communication one will send that ADP response and there will be complete
communication with this ADP protocol.