DHCP - what is this?

is well known that for each network device, be it a computer, a laptop, a tablet or a phone, must have a specific email id - IP-address, as well as set parameters mask, gateway, and data on the DNS-server.This address is the network interface connected directly trying to get on the special equipment, which is engaged in the distribution of automatic addresses.If such equipment is not, then the user has to enter the network settings manually.If multiple computers on the network, there may be errors in the addressing and duplicate addresses, leading to failures in the system and slow down the network performance.In a home network, in the absence of automatic distribution of addresses, it is necessary to register the network settings manually on each device to connect, for example, a router.Not every user has sufficient knowledge and experience to properly change these settings.Therefore, in the home, too many users are trying to expand the automatic distribution of addresses, that is, expand the server DHCP.

DHCP - what is this?

Let us examine this matter.To avoid confusion when addressing was implemented Dynamic Host Configuration Protocol (DHCP).This is a feature that provides a dynamic distribution network settings will connect the client machines.If these devices in the settings option is "to receive IP-address from a DHCP server only" service is enabled and DHCP, the entire responsibility for the correct network settings on client computers is transmitted DHCP-server.This significantly reduces the cost of support and network management and also helps to avoid mistakes in the distribution addresses.Service, including DHCP, the default start automatically when you turn on any device that supports interfaces wired or wireless network.For example, tablets or phones enough to include Wi-Fi and the found devices, distributing online, find his and connect to it.This automatically assign addresses excludes duplicate IP and consequently, avoids conflict network.

How is the distribution of addresses

During connect any device to the network is sending a special request to the broadcast network with the dealer to find the parameters of the network server DHCP.This is for a server and how important it is for a large network?So is a device that is responsible for distributing addresses to computers on the network to automatically apply them to different customers.If such a server is present, it generates a response packet to the request of the client, which may include settings such as the address of the IP, network mask, gateway parameters, addresses of DNS-servers, domain name, and so on. D., And sends the packet to the client device.The customer receives a confirmation signal from the server DHCP.The generated data packet is standardized, so it can decrypt and use almost any operating system.

options issued by the server to the client device, have a limited period of validity of a custom that has its name - "lease time".Addresses issued by the server are analyzed for a match with the existing addresses with unexpired lease time, so duplication of addresses excluded.Usually it puts a small rental period - from several hours to 4-6 days.After this period, the device repeats the request to the server and receives the same address (if it is available), or any free.

Client Settings for automatic network settings in the operating system Windows

To the client received response network settings from DHCP, you need to check a few settings in the computer's Control Panel (discussed on the example of the operating system Windows).To do this, go to the Start menu, then - in the Control Panel (which to switch to Classic View), and select "Network Connections."Choose a network connection, which is scheduled to run from DHCP, click on it with the right mouse button and go to "Properties".In the window that opens, go to the Internet Protocol TCP / IP.DHCP - what's that?It is getting automatic network settings.Therefore, we mark the points option to automatically obtain an IP-address and DNS.After making your selection, click "OK".Setting up a DHCP client is completed.Now the device will obtain the address from the DHCP-server automatically when you start Windows.

Configuring DHCP in Windows 7 is installed similarly, but the location of the properties of the adapters is a little different from Windows XP.Just go to Start - Control Panel - Control Center Network and Sharing Center.Select in the left menu, select "Change adapter settings".Then - similar to the above on the settings in Windows XP.

Setting automatic distribution of addresses in other operating systems

on Linux- and Android-devices to connect with the expanded network DHCP-server does not make any problems.It is enough to enable the network interface (wired or wireless), wait until the data exchange will take place between the device and the DHCP server and verify that the network settings are obtained and used successfully.DHCP service on almost all devices are enabled by default.

If the connection does not happen, then you need to check the status of automatic reception addresses.For example, the Android OS to do this, go to Settings - Besprovodnyve network - Settings Wi-Fi - In addition, and to make sure that the option "to use a static IP-address" is disabled.

data transmitted DHCP

Options DHCP - are parameters which are transmitted from the server to the client.All these transfer parameters are divided into categories.Any required options, such as IP-address and network mask.There nenastraivaemye service options that, for example, indicate the beginning and end of the options in the transmitted packet.At its core options - a typical key-value pairs that you can see and configure security policy.

basic DHCP options in the package, in addition to IP-addresses and masks, it is 3 (Gateways), 6 (Domain Name Servers), 44 (NBT Name Servers), 46 (NBT Node Type).These settings group, that is, can have several meanings.For example, there may be several gateway addresses or DNS-server.The values ​​of the options are configured in the DHCP-server settings.

DHCP Settings on the server

Before configuring the settings, you need to make some basic calculations options DHCP.What's that for such an option?- You ask.Options - it's all the network settings that are transmitted from the server to the client.The two main options - handed out a range of addresses and subnet mask.The entire address range of the organization is usually divided into multiple segments for different tasks, such as telecommunications, static server addresses and so forth. For static addresses are not involved in the hand, creating an additional burden on the server, ranges of addresses can be handed out to restrict.For example, when the operating range can address 1 to 10 to determine the communication, from 11 to 30 - for the server and DHCP to select the range from 31 to 254. That is, the address of any server that the clientIt will only lie in that range.You can also configure a range of addresses handed out exceptions-and they, too, will not be distributed to client devices.

Then, before you configure the DHCP server, you must determine which option it will still be handing out.Is there a need to distribute, for example, the parameters of the gateway or DNS.The data are entered on the server, run it and activate the server begins distributing addresses.

Home DHCP-server

House as DHCP-server often use routers that obtained from the content provider distributing home technology - computers, laptops, phones, televisions, and other devices connected to the network is wired or wireless manner.This creates something like a virtual server, the dealer addresses users.From the outside it looks as if a user opened at one computer a few pages in the browser.This is actually connected to an external network is only one router.This allows you to save on the number of connected lines.

Setting up automatic addressing on a router

To configure automatic distribution of home addresses of the devices you need to connect the router to your computer (laptop) power cord.In any browser prescribes the address of the router (usually proposed field request login and password by default, enter «admin» (often these data are listed in the instruction manual of the router).As a result, we see the setup menu of the router.Go to the Forums or Lan Network (name can vary) and find the sub-menu settings DHCP.How do I turn on the router distributing addresses?Just tick lines enable DHCP and reboot the router.

Configuring DHCP router

If the default settings do not suit, you can change the configuration parameters.In the same menu where we enabled the distribution of addresses, you can enter a range of IP-addresses of distribution, such as - work you can specify only two addresses, for example, a laptop and a mobile phone.This limits the number of concurrent devices that protection is the simplest connection.

Then adjust Gateway (Gataway).It is IP-address of the device through which the Internet to devices.Typically, this option is the same as the IP-address of the router.

create a basic configuration, you need to save and reboot the router.Immediately after the restart settings will take effect.

Before you disable DHCP, you must make sure that the devices are set static addresses.To turn off the automatic dispensing remove the tick from the DHCP option in the settings of the router, save your changes and reboot the device.