In this free course from ITFreeTraining I will be looking at Dynamic Host Configuration
Protocol or better known as DHCP. Before I look at what is covered in this course, I
will first look at what exactly is DHCP.
To put DHCP in its most simple terms, it is a system used to automatically configure network
devices. Consider you have a DHCP server on your network. On this network, you have a
number of devices, a computer, a phone and a printer.
In order for these devices to communicate on the network they need network configuration.
This is where DHCP comes in to play. DHCP provides network configuration to the devices
on your network. Once a device has obtained network configuration from a DHCP server,
the device can use this network configuration to communicate on the network.
Before DHCP, the administrator had to manually configure each device. On large networks with
a lot of devices, this required all the configuration to be manually recorded by the administrator.
For example, the list may have been stored using an excel spreadsheet. It was up to the
administrator to make sure the list was kept up to date. When a new device was configured
on the network, it was up to the administrator to ensure that device was not using an IP
Address that was already in use on the network.
On small networks this was possible; however, on larger networks, this became harder to
manage. Also, if configuration of a device on the network needed to change, the administrator
needed to visit each device and manually change the configuration. With manual configuration
there was always the chance of mistakes being made. A device configured incorrectly may
have problems accessing the network or not be able to access the network at all.
There are a lot of advantages of DHCP over manual configuration. These include network
configuration being able to be supplied automatically. Using automatic configuration, devices on
the network are always configured correctly assuming the DHCP server is configured correctly.
The next advantage is that configuration of devices on the network can easily and centrally
be changed. If for example, the IP Address of a DNS server were to change, it is a simple
matter to change the configuration on the DHCP server to reflect this. After the change
is made, given enough time, the DHCP server will update all the devices on the network
with the new configuration.
The last advantage with DHCP is that network configuration can easily be changed. For example,
if you have a laptop that moves from one network to another, the laptop can automatically obtain
network configuration for that network. This also applies to mobile devices like tablets
that access wireless networks. DHCP is the protocol that provides configuration to the
device so they can connect to different wireless networks. You can see that it is worth the
time to learn and use DHCP.
Now that we understand a bit about what DHCP is, I will next look at what this course will
cover. To start with, I will look at how DHCP works. There are a few components that make
up DHCP and it is important to understand how these work. Following this, I will look
at installing DHCP. This is an easy process; however, if you are using Microsoft DHCP and
Active Directory there is an extra step you will need to do before you can start using
DHCP on the network.
Next, I will look at creating a scope. A scope is a pool of free IP Addresses that gets allocated
to devices on the network. In some cases, you will want a device to always have the
same IP Address. When this occurs, I will look at how to create a reservation. This
will ensure that the same IP Address is always allocated to the same device.
Next I will look at how to use DHCP with PXE. PXE allows a device to boot from the network.
Diskless workstations require files to be downloaded from the network in order to operate.
In other cases, you may want to use PXE, for example: when performing an install from the
network.
DHCP, as we will see, uses broadcasts or multicast to communicate. This works well on a local
network, but remote clients will not be able to access the DHCP server. I will look at
a DHCP relay agent. This allows a client on a remote network to access a DHCP server when
they do not have direct access to it.
Next, I will look at the DHCP database. This contains all the network configuration that
has been allocated on the network. It is useful to know how this works in case you need to
move a DHCP install from one server to another or have problems with the database.
Following this, I will look at how to prevent unauthorized access. DHCP is a great time
saver for administrators. However, it can also allow an unauthorized device to connect
to the network and obtain access. In some cases, you may want to make it easy for a
device to access a network. For example, a free wireless access point. In other cases,
for example a company environment, you will want to put some security on DHCP to prevent
unauthorized access.
The last topic that I will look at is statistics, auditing, log file and troubleshooting. This
will help you manage your DHCP server and thus your network.
That’s all the topics for the course, if you find something missing feel free to let
us know and we will look at adding it.
Until the next video, I would like to thank you for watching the first free video in the
DHCP course. I hope to see you in the next video, all videos in this course are free.
Thanks, and see you next time.