What is DHCP

What is DHCP

　DHCP is an abbreviation for “Dynamic Host Configuration Protocol”, a protocol that automatically assigns information necessary for computers to connect to networks.

The following information can be set automatically using DHCP.

• IP address
• sub-net mask
• default router
• DNS

*Various information other than the above can be set.

　It is very convenient to be able to automatically set the information for connecting to the network such as the IP address. As more terminals connect to the network, IP addresses must be assigned for each additional terminal. If there are only a few units, this allocation work is not so difficult, but if the number of units increases, it becomes difficult to manage.

　There are rules for setting network information. For example, there is a rule that IP addresses must not overlap. If you break that rule, your network will not work well.

　Also, network settings require some knowledge of networks. Using DHCP makes it easy for users who are unfamiliar with network settings to connect.

　In this way, using DHCP makes network management easier, and the network administrator can easily centrally manage even if there are many terminals.

DHCP settings

Here, we will explain the setting of the DHCP server function and the setting of the client.

◆ DHCP server construction

　If you want to build a DHCP server in earnest, you need to build a Windows Server or Linux server, install a dedicated service program, and set it up. Here, instead of a full-fledged DHCP server setting method, we will introduce an example of building a DHCP server using a broadband router that can be easily set.

　Even if you don’t bother to build a DHCP server using a server OS, many network devices are equipped with a DHCP server function. The routers used in corporate networks also have a DHCP function. Of course, home broadband routers also have a DHCP function.

　Nowadays, the number of information terminals is increasing even in homes. We are now in an era where personal computers are owned by individuals, and terrestrial digital TVs, home-use game consoles, and portable game consoles are all connected to networks.

DHCP is very useful even in home LAN.

For example, on a broadband router, set as below.

The setting method is slightly different depending on the product, but the setting contents are almost the same.

First, create a DHCP entry to issue.

Next, set to use the functions of the DHCP server.

◆ PC network settings

　On the terminal side, just by setting “Obtain an IP address automatically”, the terminal will be able to automatically obtain an IP address.

For example, on a WindowsXP terminal, set TCP/IP properties to automatic acquisition.

In this way, the settings and work for using DHCP are easy to use and not difficult to do.