Welcome back to tour free Windows 7 course. In this video I will look at IP
Welcome back to tour free Windows 7 course. In this video I will look at IP

version 4. IP version 4 has been around since the 1970’s and has been the default protocol
version 4. IP version 4 has been around since the 1970’s and has been the default protocol

used on most networks for a long time. IP version 6 has since been developed and is
used on most networks for a long time. IP version 6 has since been developed and is

being used but from the estimates I have seen it may be about another 10 years before the
being used but from the estimates I have seen it may be about another 10 years before the

majority of the internet is running IP version 6. What this means is that you need to have
majority of the internet is running IP version 6. What this means is that you need to have

a good understanding of both protocols for a long time to come.
a good understanding of both protocols for a long time to come.

An IP version 4 address is made up of 4 bytes. 8 bits is referred to as a byte, but in
An IP version 4 address is made up of 4 bytes. 8 bits is referred to as a byte, but in

IPv4 8 bits can also be referred to as an octet. If I take a standard IP version
IPv4 8 bits can also be referred to as an octet. If I take a standard IP version

4 address it is common for it to be divided up into four parts. These four parts can be
4 address it is common for it to be divided up into four parts. These four parts can be

converted into binary. If you are not sure how to covert numbers to binary see are other
converted into binary. If you are not sure how to covert numbers to binary see are other

video on converting decimals to binary. Having a 32 bit address may seem like a lot
video on converting decimals to binary. Having a 32 bit address may seem like a lot

of addresses, but if you consider now days just about everything is being connected to
of addresses, but if you consider now days just about everything is being connected to

the internet. For example cell phones, vending machines and tablet pc’s. This is a lot
the internet. For example cell phones, vending machines and tablet pc’s. This is a lot

of devices that require an IP address. Depending on which study you look at, in 2007 there
of devices that require an IP address. Depending on which study you look at, in 2007 there

were over 2 billion PC’s used worldwide. Given that there is 4 billion addresses you
were over 2 billion PC’s used worldwide. Given that there is 4 billion addresses you

may think that they is some room left to expand, but of these address as you will soon learn,
may think that they is some room left to expand, but of these address as you will soon learn,

not all are useable. This occurs either by design or when the addresses are divided up
not all are useable. This occurs either by design or when the addresses are divided up

in a process called subnetting. If you look at the IP version 4 address space
in a process called subnetting. If you look at the IP version 4 address space

as a piece of pie, out of this pie 6% is reserved. Maybe one day these IP addresses may be useable
as a piece of pie, out of this pie 6% is reserved. Maybe one day these IP addresses may be useable

but at present with the design of IP version 4 they are not. Next there are multicast addresses.
but at present with the design of IP version 4 they are not. Next there are multicast addresses.

These addresses take up another 6%. Multicast addresses perform an important role on IP
These addresses take up another 6%. Multicast addresses perform an important role on IP

networks. Lastly you have 1% that is used for loopback and privates addresses.
networks. Lastly you have 1% that is used for loopback and privates addresses.

This means that 87 percent of the address space can be allocated and is routable on
This means that 87 percent of the address space can be allocated and is routable on

the internet. Or about 13% is not available for public use. This may not seem like a lot
the internet. Or about 13% is not available for public use. This may not seem like a lot

but this translates to just over 570 million IP addresses. On the 2nd of February 2011
but this translates to just over 570 million IP addresses. On the 2nd of February 2011

IANA allocated the last block of public IP version 4 addresses. This may sound scary
IANA allocated the last block of public IP version 4 addresses. This may sound scary

but the reality is that these addresses are allocated to ISP’s or countries and have
but the reality is that these addresses are allocated to ISP’s or countries and have

not been re allocated as yet. Depending on how fast they use there allocated addresses
not been re allocated as yet. Depending on how fast they use there allocated addresses

it could take as little as months or even years before they run out. In the future you
it could take as little as months or even years before they run out. In the future you

may have to shop around to get a public IP version 4 addresses as they start running
may have to shop around to get a public IP version 4 addresses as they start running

out. You may even have to share it with someone else.
out. You may even have to share it with someone else.

So let’s have a close look at how IP addresses are allocated. First I will start with private
So let’s have a close look at how IP addresses are allocated. First I will start with private

addresses. Private addresses are IP addresses that are not routable on the internet. This
addresses. Private addresses are IP addresses that are not routable on the internet. This

means you are free to allocate these addresses any way you want. Companies commonly use these
means you are free to allocate these addresses any way you want. Companies commonly use these

IP addresses on their internal network.
IP addresses on their internal network.

The first type of these addresses start with a 10. This gives you just over 16 million
The first type of these addresses start with a 10. This gives you just over 16 million

hosts on the one network. The second address starts with 172 dot 16 and ending in 172 dot
hosts on the one network. The second address starts with 172 dot 16 and ending in 172 dot

31 giving you just over 1 million hosts. The last private addresses starts with 192 dot
31 giving you just over 1 million hosts. The last private addresses starts with 192 dot

168 and give you just over 65000 hosts. It would be hard to find a network anyway with
168 and give you just over 65000 hosts. It would be hard to find a network anyway with

this many computers on it. So how do you make more efficient use of all these IP addresses?
this many computers on it. So how do you make more efficient use of all these IP addresses?

To do this you use a process called subnetting. Subnetting is simply the process of dividing
To do this you use a process called subnetting. Subnetting is simply the process of dividing

a large network into smaller networks. If I were to take the network 10 dot 0 dot 0
a large network into smaller networks. If I were to take the network 10 dot 0 dot 0

dot 0. I can divide this network into smaller parts by applying a subnet mask.
dot 0. I can divide this network into smaller parts by applying a subnet mask.

A subnet mask is simply a number of unbroken 1’s. Given a subnet mask of 8 bits means
A subnet mask is simply a number of unbroken 1’s. Given a subnet mask of 8 bits means

out of the 32 bits of an IP version 4 subnet mask the first 8 are set to one. This can
out of the 32 bits of an IP version 4 subnet mask the first 8 are set to one. This can

be shown as slash 8 after the IP address or the subnet mask as 4 octets in this case,
be shown as slash 8 after the IP address or the subnet mask as 4 octets in this case,

255 dot 0 dot 0 dot 0. If you take the private network 10 dot 0 dot
255 dot 0 dot 0 dot 0. If you take the private network 10 dot 0 dot

0 dot 0 with the subnet mask of 8 bits, this will give you over 16 million hosts. Not even
0 dot 0 with the subnet mask of 8 bits, this will give you over 16 million hosts. Not even

the largest network has this many hosts on the one network segment so more than likely
the largest network has this many hosts on the one network segment so more than likely

you are going to want to divide this network up into smaller parts.
you are going to want to divide this network up into smaller parts.

If I increase the number of bits used in the subnet mask you can see the number of networks
If I increase the number of bits used in the subnet mask you can see the number of networks

goes up and the number of hosts per network goes down. When deciding on which subnet mask
goes up and the number of hosts per network goes down. When deciding on which subnet mask

to use, it is a case of simply deciding on how many networks you want and how many hosts
to use, it is a case of simply deciding on how many networks you want and how many hosts

you want per network. When thinking about subletting it is easy
you want per network. When thinking about subletting it is easy

to conceptualize when you consider a piece of pie. If I were to take the private network
to conceptualize when you consider a piece of pie. If I were to take the private network

10 dot 0 dot 0 dot 0 and use an 8 bit subnet mask this gives me one network, basically
10 dot 0 dot 0 dot 0 and use an 8 bit subnet mask this gives me one network, basically

all the pie. If I divided the network into two, notice that I get two networks now. Notice
all the pie. If I divided the network into two, notice that I get two networks now. Notice

also that the number of bits in the subnet mask has changed to 9.
also that the number of bits in the subnet mask has changed to 9.

You don’t always have to break the network down by halving it. You could for example
You don’t always have to break the network down by halving it. You could for example

divide half the network here in four pieces. Each time I divide the network down it also
divide half the network here in four pieces. Each time I divide the network down it also

changes the number of IP addresses that are available in that network.
changes the number of IP addresses that are available in that network.

Getting a little bit more creative I could divide one segment up into 3 parts. You can
Getting a little bit more creative I could divide one segment up into 3 parts. You can

see the parts won’t be the same size as binary works off multiples of two. As long
see the parts won’t be the same size as binary works off multiples of two. As long

as you use the right size subnet mask and you don’t have an overlap of IP addresses
as you use the right size subnet mask and you don’t have an overlap of IP addresses

on two different networks you are free to divide the network any way you want.
on two different networks you are free to divide the network any way you want.

With careful planning this should not occur and you should have an IP addresses that do
With careful planning this should not occur and you should have an IP addresses that do

not overlap. The easy way to check this is to write down the start and end IP address
not overlap. The easy way to check this is to write down the start and end IP address

down for each of your network and make sure that none of them overlap.
down for each of your network and make sure that none of them overlap.

In the real world it is doubtful that you would subnet a network in this way. Working
In the real world it is doubtful that you would subnet a network in this way. Working

with subnet masks that are multiple of 8’s are easier to work on. For example, I could
with subnet masks that are multiple of 8’s are easier to work on. For example, I could

use a subnet mask of 24bits or 255 dot 255 dot 255 dot 0.
use a subnet mask of 24bits or 255 dot 255 dot 255 dot 0.

This will give me 254 usable hosts per network. On most networks this should be enough. But
This will give me 254 usable hosts per network. On most networks this should be enough. But

just image you had a network with 200 computers. There is enough room to expand but the company
just image you had a network with 200 computers. There is enough room to expand but the company

decided to use IP based telephones. All of a sudden you need 200 more IP addresses for
decided to use IP based telephones. All of a sudden you need 200 more IP addresses for

each employee in the company. In this case you can use a technique called
each employee in the company. In this case you can use a technique called

super netting. Super netting is the process of taking multiple networks and combining
super netting. Super netting is the process of taking multiple networks and combining

them into one. To do is it is a simple matter of decreasing the number of bits in the sub 0:08:26.910,0:08:36.560,0 net mask. In this example, I could use a subnet mask of 23 bits or 255 dot 255 dot 254 dot
them into one. To do is it is a simple matter of decreasing the number of bits in the sub 0:08:26.910,0:08:36.560,0 net mask. In this example, I could use a subnet mask of 23 bits or 255 dot 255 dot 254 dot

0. When doing this again you have to ensure that there is no overlap on your network.
0. When doing this again you have to ensure that there is no overlap on your network.

Once you have decided on your network you
Once you have decided on your network you

need to configure your clients with an IP address. On most networks you have a DHCP
need to configure your clients with an IP address. On most networks you have a DHCP

server that will allocate your IP configuration. In some cases the DHCP server may be down
server that will allocate your IP configuration. In some cases the DHCP server may be down

or there is no DHCP server on the network. For example you plug your computer in to a
or there is no DHCP server on the network. For example you plug your computer in to a

home network. When this occurs windows uses a system called
home network. When this occurs windows uses a system called

APIPA to allocate an IP address to the computer. APIPA or automatic private IP addressing automatically
APIPA to allocate an IP address to the computer. APIPA or automatic private IP addressing automatically

allocates a random IP address from the network 169 dot 254 dot 0 dot 0.
allocates a random IP address from the network 169 dot 254 dot 0 dot 0.

When used correctly you should be able to connect multiple computers on the same network
When used correctly you should be able to connect multiple computers on the same network

with no Infrastructure. These computers should be able to communicate with each other without
with no Infrastructure. These computers should be able to communicate with each other without

any additional configuration. The disadvantage of APIPA is that it is not routable. Computers
any additional configuration. The disadvantage of APIPA is that it is not routable. Computers

with an APIPA address will only be able to communicate with other computers on the local
with an APIPA address will only be able to communicate with other computers on the local

network with an APIPA address. To demonstrate APIPA a little bit better,
network with an APIPA address. To demonstrate APIPA a little bit better,

I will switch to my windows 7 computer. I have switched off the DHCP server on this
I will switch to my windows 7 computer. I have switched off the DHCP server on this

network forcing this computer to get an APIPA address instead. If I now open a command prompt
network forcing this computer to get an APIPA address instead. If I now open a command prompt

from the start menu and run the command ip config you can see that this computer has
from the start menu and run the command ip config you can see that this computer has

been given an APIPA address. APIPA addresses will always start with 169
been given an APIPA address. APIPA addresses will always start with 169

dot 254. Notice that there is no default gateway. APIPA addresses are not routable on the internet
dot 254. Notice that there is no default gateway. APIPA addresses are not routable on the internet

and will only work on the local network with other APIPA addresses.
and will only work on the local network with other APIPA addresses.

When you are troubleshooting network problems and you notice that the computer is getting
When you are troubleshooting network problems and you notice that the computer is getting

an APIPA address rather than an IP address from a DHCP server, this generally indicates
an APIPA address rather than an IP address from a DHCP server, this generally indicates

that there is a physical problem with the network. I would first check the cables and
that there is a physical problem with the network. I would first check the cables and

make sure they are in correctly. A network cable that is half in will sometimes be enough
make sure they are in correctly. A network cable that is half in will sometimes be enough

to have the network adapter light come on but will still prevent it from sending traffic
to have the network adapter light come on but will still prevent it from sending traffic

on the network. The end result is you will get an APIPA address.
on the network. The end result is you will get an APIPA address.

The IP config command can also give you additional information about your adapter by adding the
The IP config command can also give you additional information about your adapter by adding the

slash all switch. Information includes the unique mac address assigned to the card and
slash all switch. Information includes the unique mac address assigned to the card and

the name and domain member ship of the computer. I have restarted the DHCP server. If I now
the name and domain member ship of the computer. I have restarted the DHCP server. If I now

run the IP config command again with the slash renew switch, you will see that the computer
run the IP config command again with the slash renew switch, you will see that the computer

will get a valid IP address off the DHCP server. If you don’t want APIPA to assign an IP
will get a valid IP address off the DHCP server. If you don’t want APIPA to assign an IP

address to your network adapter you can open the control panel and select network and internet
address to your network adapter you can open the control panel and select network and internet

and then select network and sharing center. From here select change adapter settings.
and then select network and sharing center. From here select change adapter settings.

This will show all the network adapters currently installed on your system. To configure the
This will show all the network adapters currently installed on your system. To configure the

IP configuration for the network adapter select the adapter and open the properties. Once
IP configuration for the network adapter select the adapter and open the properties. Once

open select the IP version 4 protocols and select properties.
open select the IP version 4 protocols and select properties.

From here you can see the tab alternative configuration. This is the configuration that
From here you can see the tab alternative configuration. This is the configuration that

is used when a DHCP server could not be located. It is just a matter of entering in the details
is used when a DHCP server could not be located. It is just a matter of entering in the details

here. If you have a laptop that use on your home network and company network that needs
here. If you have a laptop that use on your home network and company network that needs

a special IP address when at home, this is the place to set it so it does not affect
a special IP address when at home, this is the place to set it so it does not affect

your configuration when it is in the office. This concludes IP version 4. In the next video
your configuration when it is in the office. This concludes IP version 4. In the next video

I will look at IP version 6. For free questions and exam study guides make sure you visit
I will look at IP version 6. For free questions and exam study guides make sure you visit

our web page. Thanks for watching.
our web page. Thanks for watching.