hello my name is Jason Johnson and thank you for watching my videos I hope you
find that they're helpful and thank you for subscribing to my channel and thank
you for sharing them with others if you have any questions or feedback you can
leave those in the comments below and I'll try to get an answer back to you as
quick as possible or point you in the right direction this video is going to
be chapter 7 chapter 7 and chapter 7 networking concepts it is a two-part
video this is part 2 of 2 so you will find a link in the description below
that will point you to part 1 of two so the first video will be uh
there's a link in the description below in part two we're going to talk about
basic networking concepts and technologies and how to configure
network connectivities between computers or in pcs so let's take a look at basic
networking concepts and technologies now when we're talking about basic and this
is a basic level we're going to talk about the networking technology some of
the terms that you need to know and some of the information is for example a MAC
address or a machine address code that's hard coded on to the network interface
card or your NIC card by the manufacturer the MAC address is a 48 bit
hexadecimal representation so it's a it's basic team numbering system so you
go from 0 to 9 and then after you get to 9 instead of going to 10 you start off
with a and then you go all the way up to the letter F so you have base 16 and
I've got some videos on binary to decimal conversion I don't think I have
a video yet on hexadecimal but I will here in the future so you can check
those out on my youtube channel and when you write that in there you have a
hexadecimal format usually and this goes beyond the scope of this video but I'm
just going to show you real quick usually the manufacturer and I'm going
to make this a little bit smaller here the manufacturer has the first digits
here they are assigned that by a organization or a governing body and
then the last part here is then assigned locally by the manufacturer so if you
are a company that's manufacturing network interface cards using the
Ethernet standard or using a wireless standard but if you are making network
interface cards you are assigned a hexadecimal number exist 'm and then you
are given that first part and then the second part is internal you can usually
take a MAC address on a NIC card and you can find that card and you can look it
up on the internet and you can find out who manufacture that card which is an
interesting thing to do I do that with some of my students sometimes we will
pull MIT cards out and we will look those up on the internet to see where
those were made but those are hexadecimal numbers that
you better represent it on there we also have another term in the term that you
need to understand that's Internet Protocol or IP when we talk about
Internet Protocol that is assigned by network administrators based on the
location within the network so you can either be assigned manually an IP
address or your Internet Protocol address or it can be assigned with
something about like a DHCP server which is uh it has a pool of IP numbers that
just passes those out and that's what most local area networks do today is we
have some type of DHCP server that just sends that information out as requested
now there's two versions of the IP protocol that we're currently using we
have ipv4 or v4 and if you want to know more about networking by the way I've
got a whole series on the first course for the CCNA series the Cisco Academy
the Cisco Networking Academy and you can check that out on my playlist I'll have
a link in the description below as well for that and you can learn about v4 and
you can learn about v6 and that's a whole nother series and a whole another
course with the Cisco Networking Academy but v4 is a 32 bit a 32 bit IP address
it's written in dotted decimal if we are running out of we have ran out of 32 bit
out of the v4 addresses so we've moved to the v6 it was first up finalized in
1995 and a lot of devices or most devices in 2017 are moving to the v6
version now it's a hundred and twenty eight bit and it's written in
hexadecimal it has a lot more IP addressing it just gives us a much much
much deeper pool of IP addressing now to use but we write that in a hexadecimal
at 128 bit IP V format you'll kind of you're going to see that written out
something like this me know 192 168 you know 208 that's probably one the one
you're more familiar with the v6 address format is 128-bit it's
written EXA decimal and you have these hex tests these are octet so you have
four octet and an octet being you know eight eight bits over here you're
writing these in hex tats and so you have 128 bits and you have one two three
four five six seven eight hex tats and it's 128 bits long and this is a way to
write it in compressed format and I'm not going to really discuss it in this
video here but you can compress v6 addresses down and you can write them
you know eliminate hex tests of zeros for example like these here we've
eliminated one two and three we've just collapse those down well we know there's
eight hex tests so we know that there are 1 2 3 4 5 so we know that there's
three sets of zero HEC stats in there you can't eliminate hex tests and I'm
just going to I'm going to explain it a little bit here in this video but I've
got other videos in the networking academy the the routing and switching
networking academy videos that talk about it even more in depth but you if
you let's say that I had zeros here and here
I can't collapse these and these because then I wouldn't know where the collapse
is and you can also eliminate leading zeros you can't eliminate trailing zeros
but that can eliminate leading zeros so for example I can write that as 200 and
I just know that there's a zero at the front of it because I know I have four
characters in that hex tap on there so explains a little bit more in depth what
you're actually going to get this class but I know it's important to understand
that when you're looking at it and again check out my videos up on the it's the
routing and switching or R and s for the 5.1 version of the cisco networking
academy there's more videos there that will help you with ABI for in the v6
addressing scheme now when we connect host devices
together they need to have addresses to communicate on the network and MAC
addresses do not change when devices move from one one network to another MAC
addresses and I'm going to say it again MAC addresses are hard-coded to the NIC
card or your network interface card you can what I call spoof MAC addresses you
can make make the network think that it's got a different MAC address and
that's that's fairly easy to do in the networking world and that's how you do
some kind of a Mac man in the middle attacks and you do some kind of spoofing
on a wireless network some things like that if you if you've said on a wireless
network so only certain MAC addresses connect can connect
well you can fool that network into thinking that it's a different MAC
address but as a general rule of rule of information MAC addresses do not change
on that NIC device IP addresses do change because they're based on software
they're based on where the network is devices in the network so for example if
I have this end device inside this local area network over here and it's got an
address of you know 192 168 10 dot to say 10 dot 2 1 9 2 1 6 8 and I'm just
giving that a v4 my handwriting is really bad here we're trying to draw
with my mouse and when I move it over here my IP addressing scheme over here
is 192.168.1.1 T dot something and then let's say it's going to be 22 over here
so my and then based upon a slash 24 and that's way beyond the scope of this
video so I apologize for throwing that in there but again I've got videos that
show you how to do IP unsub netting and so these are going to be based upon the
location so this device here if I move it from here over to here it's going to
get a different IP address because it needs to it needs to have an address IP
addressing scheme for this local area network which is going to be different
than the one over here in there they've got it there 208 and over here 309 8 iu
just lightly different one
okay so some another so some other points that you need to memorize or need
to know is that a v4 address has composed of two parts the first part
identifies the network and the second part identifies a host on the network
and I've got videos on subnetting by the way I have a link in the description on
that as well which helps you with subnetting helps you figure out you know
what subnets on which one and all of that so I've got videos on that but a
computer router uses a subnet mask to calculate the network portion of the
destination ipv4 address so and I'm just going to try to explain this in real
quick simple terms when a network device or an in device starts reading the
packet of information and it says this is your IP address it starts reading the
ones and zeros and it says okay I'm reading 192 168 and it starts reading
these binary numbers and it says a read those and then it says what's my subnet
mask and if you notice here it's got all ones in here well the networking device
starts reading across in this binary says one one one one one all wait till
it gets to a zero and it says oh okay well all of those previous bits all of
these previous ones are my network coat or my network portion of the on there so
it says ok so that IP address that I just received this part here is my
network and everything to the right of that first zero this first zero and
everything to the right of that everything to the right of the last one
let me say it that way is my host portion so all of this over here is my
host portion and that's determined by your subnet mask so the the subnet mask
that you put in is going to you know be once and where the one ends everything
to the right of that is going to be the host portion I don't expect you to get a
full understanding of you know networking portion and host portion but
I just trying to give you a high-level overview here on that
okay and and so your network ID or if I was going to say this is a slash 24
because we're using 24 bits 8 16 24 and so that's a slash 24 and so this network
this ID address I would just hand this to somebody and I would say here's your
address I have 192 168 dot 200.000 how many addresses I have in here and I know
I can divide this up and then they can do subnetting from there and again I've
got videos on how to do subnetting and how to understand and read that and the
description is below on those so and I apologize for keep saying that but I
just I just know it's easier to point you to another video then try to explain
it here in this one which I don't have enough time to do now when we have a v6
address and we have to collapse it here are the rules I talked about it briefly
earlier on a previous slide but I'm going to just show you again really real
quick there's two rules one is you can omit leading zeros and rule tool is you
can omit all zero segments so on here I can eliminate the leading zero and write
that like this I can also take a block and say all of the contiguous zero
segments I can eliminate those and write it with just a colon colon however I
cannot eliminate two non contiguous zeros segments so I can't know if I had
zero zeros over here I couldn't eliminate both of them and I explained
that earlier because you need to know how where you're missing octet sar so
for example this one here I can eliminate all my leading zeros and I can
write it this way or I can write it where I compressed it all the way down
and that's an F F 0 2 colon colon 1 well I know that there are still six missing
hex tetes in there so I could just fill in 6 0 1 2 3 4 5 6 I can fill in 6 hex
tests of zeros in there and the computer does the same thing it just reads that
colon colon it knows that there is missing or it's compressed 6 HEC stats
in there ok so transport layer protocols you need to
have a high level understanding of the protocols transport layer protocols
there's two of them that we use at that that's the TCP and the UDP transport
control protease P is considered reliable it ensures that all the data
arrives at the destination that's going to be for an example when you're sending
a file across the network and the protocol is going to be used for TCP to
send that because it needs to know all the data got there a UDP is does not
provide for any reliability an example for that might be IP you have an IP
phone or you're streaming a video let's just say that you connect to a YouTube
video when you're streaming or you're on a digital call or an IP call Internet
Protocol telephony call and the reason that UDP does not provide for
reliability is because it's faster it doesn't take as much data because you
don't have a connect you don't have a back and forth connection it doesn't
require acknowledgments it does not resend lost data and it delivers data as
it arrives so it just it the information comes in and you hear it you hear a
voice talking on the phone you watch a video and sometimes you may be missing
data and that's okay because it may it might skip a few frames but you just you
know we fill in the difference on there so you might miss a word and then you
can just say to the person hey can you repeat yourself well with the TCP it
needs to be reliable because we need to know that everything on that web page
got delivered to us we need to know that everything in that file got delivered to
us all of the bits are important and so those packets get sent and everything
gets acknowledged it resends lost data and it delivers the data in a sequence
order because that data needs to be put back together for a file for example or
for a webpage needs to be displayed in a certain way it can't just be jumbled up
all over the place it needs to be formatted properly and so that's what
TCP provides for us versus UDP and you may say to yourself why don't just
everything except use TCP well we still have bandwidth issues and we still try
to keep data to a minimum because it does cost money to send that data across
the network so we try to keep that as at a minimum as much as possible and we use
protocols that help with that now with the transport layer protocols you do
need to have a really good understanding of what we call the well known
ports and well-known ports are going to be everything from TCP for 2021 for FTP
you know you might be setting up a you know going to a web server and that's
port 80 or hypertext Transfer Protocol 443 is the hypertext or HTTP or
hypertext Transfer Protocol secure that's where you encrypt your data for
web for web pages and so you need to be familiar with this page here with these
port numbers and if you want to look those up on the internet if you want to
look those up in your material those are what we call well-known port numbers and
so these are set by the standard you know the governing body set these
everybody abides by it and so different different services use different port
numbers and that's why we know that they're well-known for example a DCP
server is going to use 67 and 68 for server and client okay so that wraps up
this video and that's part two of chapter seven we discussed some
different things in these in these two different videos but both Part one and
Part two we talked about different types of networks LANs man's LANs cans we
talked about peer-to-peer and client-server we talked about the tcp/ip
model we talked about a CS csma/cd versus csma/ca we talked about coax
cables we talked about the cabling standards t568a and t568b t568b we
talked about MAC addresses IP addresses we talked about the transport layer
protocol and then the differences between TCP and UDP and how one is
connection oriented one of them is connectionless all right so I hope you
enjoyed this video I hope it was helpful for helpful for you in your studies if
it was helpful for you you know I love to hear from students but I love to hear
from people that are watching my videos so leave a comment below I'll interact
with you if you want that if not just you know congratulate I appreciate any
feedback if you think that there's anything that I can do to improve my
videos I do appreciate that feedback as well so again I hope the videos will
help well thank you for subscribing thank you for sharing my videos with
others and I hope you have a great day you