-: IP Addressing. 2 2
Welcome to this section of the course 3 3
where we're going to start discussing IP addressing. 4 4
Now, you may be wondering what exactly is an IP address? 5 5
Well, an IP address, 6 6
also knows as an Internet Protocol Address, 7 7
is an assigned numerical label 8 8
that's used to identify internet communicating devices 9 9
on a computer network. 10 10
IP addresses are used at Layer 3 of the OSI model, 11 11
and they're also used by routers to be able to send data 12 12
from one network to another network. 13 13
Remember, when we're dealing with two devices 14 14
that are internal to our own network or LAN, 15 15
we're usually going to be dealing with Layer 2 addressing, 16 16
which is based on MAC addresses. 17 17
And that data is going to be forward around the network 18 18
via our network switches. 19 19
But, once we start going to two different networks 20 20
or even two different subnets, 21 21
we have to start using Layer 3 addressing 22 22
with our IP addresses. 23 23
Now, let me give you an analogy 24 24
that will help you understand 25 25
how IP addresses actually work. 26 26
Let's pretend that an IP address 27 27
is just like a mailing address for your home, 28 28
but we're going to use it for a computer. 29 29
Now, if I was going to send you a letter at home, 30 30
I have to have a way to uniquely identify your house 31 31
from all the other houses 32 32
that are located on the same street or within the same city. 33 33
Now, each house can stand on its own 34 34
and it can be built wherever you want it to be. 35 35
Regardless of whether it has an assigned address to it 36 36
on the front of the house or not. 37 37
This would be equivalent of me powering on my laptop 38 38
while not being connected to any networks. 39 39
Now, as long as nobody needs to know where my laptop is, 40 40
it doesn't really matter. 41 41
I can be anywhere I want, 42 42
because nobody's going to be sending me any data. 43 43
And in this case, I won't need an IP address. 44 44
Just like your house, doesn't need an address 45 45
if nobody has to send you any packages. 46 46
But if somebody wants to be able to go over to your house 47 47
or to send you a package, 48 48
they need to know how to get from one house to another. 49 49
And that's where you're going to need to know 50 50
the house number, the street, and the city name 51 51
so you can find it. 52 52
This would be the equivalent of having an IP address 53 53
assigned to my laptop. 54 54
Because once I have that IP address assigned 55 55
people can now send me data 56 56
and I can communicate with other people on the network. 57 57
Now, going back to my house example. 58 58
If you want to be able to communicate with people, 59 59
you need to know their house number, their street, 60 60
their city, and their state 61 61
that makes up their complete mailing address. 62 62
This way you can send them a package or a letter 63 63
and it will get to them, right? 64 64
Well, here in the United States, 65 65
we have a standard format for any letter or package 66 66
that we want to send and have it delivered 67 67
by the postal service. 68 68
The first line always has your house number 69 69
and a street name, something like 123 Main Street. 70 70
The second line is always going to have your city, 71 71
your state, and your ZIP code. 72 72
So it might be something 73 73
like San Juan, Puerto Rico, 00918. 74 74
This happens to be the information that we use 75 75
for Dion Training's office. 76 76
Now, when you're using the standard format, 77 77
the postal system is able to figure out 78 78
how to send the letter from your house to my office, 79 79
Because everybody knows the same common format 80 80
that we're all going to be using and how we can all read it. 81 81
So when a letter is going to be sent from your home 82 82
to my office, the post office first starts 83 83
at the second line, which is more generic. 84 84
This had my city, my state, and my ZIP code. 85 85
So the post office is going to look at the address 86 86
on your letter and determines if it can be delivered 87 87
by the same post office. 88 88
For example, if you happen to be in the same city as me, 89 89
our local post office will take it from my house to them, 90 90
and then from them to you. 91 91
You see in our postal system, each post office 92 92
is going to provide service to only one ZIP code. 93 93
So if you mailed the letter 94 94
from Beverly Hills, California, 95 95
that post office services the 90210 ZIP code. 96 96
And they're going to look at this letter 97 97
that you're trying to send to my office in Puerto Rico, 98 98
and they're going to see the ZIP code of 00918. 99 99
Those two ZIP codes don't match. 100 100
And since we're not in the same ZIP code, 101 101
that means they're going to have to go 102 102
and check the state or territory 103 103
that's listed on that second line. 104 104
In this example, the state or territory that we're using 105 105
is the island of Puerto Rico, 106 106
which is a territory of the United States. 107 107
So they're going to take the letter 108 108
from the Beverly Hills Post Office and forward it 109 109
to the distribution center, 110 110
which happens to be in Los Angeles, California. 111 111
This is then going to put on a truck 112 112
and go to that mail distribution center. 113 113
Now, once it gets to Los Angeles, 114 114
it's going to go on another truck and they're going to send it 115 115
to the South Eastern part of the United States, 116 116
to the mail distribution center 117 117
located in Jacksonville, Florida. 118 118
Once it gets to Jacksonville, Florida, 119 119
they're going to look at that city and state, 120 120
and see is it within Florida. 121 121
If it is, they load it on a truck 122 122
and send it to the general area, 123 123
either North Florida, Central Florida, or South Florida. 124 124
And then, it will keep getting forwarded, 125 125
more and more specific, until it reaches 126 126
the final destination city. 127 127
But in our case, this letter actually 128 128
needs to go to Puerto Rico. 129 129
So we can't put it on a truck. 130 130
Instead, we're going to put it on a boat 131 131
from Jacksonville Harbor. 132 132
And it's going to go from their main distribution center 133 133
to the regional distribution center, 134 134
located down in San Juan, Puerto Rico. 135 135
Now, once it gets down to San Juan, Puerto Rico, 136 136
this actually services Puerto Rico and the Virgin Islands. 137 137
Once it gets there, 138 138
they're going to look at that state territory line. 139 139
And they're going to see it's going to Puerto Rico, 140 140
which happens to be the same island this letter is now on. 141 141
So their regional facility, 142 142
which also happens to be in San Juan, 143 143
is going to look at that exact city that I wanted it to go to 144 144
by looking at the city and ZIP code. 145 145
In this case, 146 146
it needs to go from the main distribution center in San Juan 147 147
to the local post office in San Juan. 148 148
And because San Juan is a big city, 149 149
with over a million people in it, 150 150
there are a lot of different ZIP codes 151 151
and different post offices within the City of San Juan. 152 152
So they're going to check the ZIP code 153 153
and find out that this letter 154 154
needs to go to the San Juan Post Office, 155 155
that services the 00918 ZIP code. 156 156
So once again, our letter is put on a truck and it's moved. 157 157
This time, it's going from the regional center 158 158
to the local post office of 00918 in San Juan, 159 159
which will then allow it to be delivered to the end-user. 160 160
So, this letter now makes it to the local post office, 161 161
but it's still not done being moved. 162 162
At this point, we've done all the big bulk movements. 163 163
We've gone from state to state, and city to city. 164 164
And now, we are down at the local post office 165 165
that services my office, 166 166
but I don't have that letter in my hands yet. 167 167
So now, this post office at 00918 168 168
is going to check all the street addresses 169 169
for all the letters that they've received that day. 170 170
And they're going to put it onto the right truck 171 171
with the right mail person that delivers to that street. 172 172
Because each mail person usually delivers 173 173
to 10 or 20 streets per day. 174 174
Now, once this mail person has my letter, 175 175
they're going to deliver it by driving around the neighborhoods 176 176
until they reach my street. 177 177
And then, they're going to locate my office 178 178
by using the number located on our building. 179 179
In our example, 123, which was located on Main Street. 180 180
Now this is a ton of movement and routing, 181 181
and forwarding of this piece of mail 182 182
to get it from Beverly Hills, California, 90210, 183 183
to San Juan, Puerto Rico, 00918. 184 184
And this all happens in about a week, 185 185
and all for the cost of a first-class stamp 186 186
at around 60 cents. 187 187
Now that sounds like a pretty good deal to me, right? 188 188
Unless you're the mail carriers, 189 189
you have to make this all happen. 190 190
Now let's jump back to our networks and our computers. 191 191
The same type of thing happens with our data, 192 192
but we don't have to put a first-class stamp on it. 193 193
Instead, we're going to make sure it gets routed 194 194
until it finds the right location. 195 195
And that location is determined 196 196
by the IP address of the source and destination. 197 197
So if you want to communicate with other computers 198 198
outside your network or sub-net, 199 199
you need to know their IP address. 200 200
That becomes the destination. 201 201
An IP address can come in one of two formats. 202 202
IP addresses can either be IPv4 or IPv6. 203 203
This stands for Internet Protocol version 4 204 204
or Internet Protocol version 6. 205 205
In this section of the course, 206 206
we're going to discuss both of these formats 207 207
and why each one is used, 208 208
and how information is going to flow 209 209
at Layer 3 of the OSI model, 210 210
using these two different types of IP addresses. 211 211
Now we're going to be working 212 212
in domain one, Networking Fundamentals, 213 213
throughout this entire section of the course. 214 214
We're going to be covering two objectives in this section, 215 215
specifically Objective 1.4 and 1.6. 216 216
Now, Objective 1.4 is where we're going to spend 217 217
most of our time. 218 218
It states that given a scenario, 219 219
you must be able to configure a sub-net 220 220
and use appropriate IP addressing schemes. 221 221
Objective 1.6 will also be briefly covered 222 222
because it states you must be able to explain the use 223 223
and purpose of network services. 224 224
So let's jump into IP addressing 225 225
in this section of the course.