What is a DHCP Server?
A DHCP server is a network device that assigns IP addresses to devices on a network. For example, the DHCP server will assign an IP address from its pool of available IPs to any host requesting one from it. The process of assigning an IP address by a DHCP server is called Dynamic Host Configuration Protocol (DHCP) leasing.
How does DHCP work?
The DHCP server is part of the Dynamic Host Configuration Protocol (DHCP) networking protocol. A network administrator uses a DHCP server to configure devices like computers, printers, and routers on an IP network without having to remember specific hardware addresses or manually assign permanent configurations.
DHCP is a networking protocol consisting of three types. The DHCP is commonly used on home networks to automatically assign an IP address and other connection information, the BOOTP for dynamic configuration in diskless workstations, and the failover between two servers to ensure the availability of service.
When using DHCP (or BOOTP), each networked device is configured to automatically request IP addresses and other information from a DHCP server. The server dynamically assigns an IP address, based on the available network configuration for that particular host machine.
The DHCP server manages a pool of IP addresses (called the scope) and provides them to clients on an as-needed basis. These addresses are assigned for specific lengths of time known as leases, which allow devices that use these IPs to temporarily remain connected with full connectivity without having to reestablish their settings.
It is possible to have a DHCP server located on the local network or at a remote location, offsite. In most cases, it will be necessary for this device to provide IP addresses from different address ranges than those used by devices that are directly attached to the router itself. This allows simultaneous use of static IPs and automatic assignment.
How do I find my DHCP server in windows?
In the search box on your taskbar, enter cmd. When you see “Command Prompt” in the list of results, right-click it and select Run as Administrator. When prompted by the User Account Control dialogue to allow this app to make changes to your PC click Yes. Type ipconfig /all at a command prompt. The DHCP server is displayed as your default gateway under the heading Default Gateway.
What are DHCP Leases?
When a client requests an IP address, the DHCP Server checks its pool of available addresses and assigns one to that client for a specific length of time. This temporary assignment is called a “lease“. Typically, leases expire after a few days, so DHCP servers usually do not have to deal with the task of re-issuing an IP address that is about to expire.
While a client’s lease period is in effect, it can use its assigned IP for any purpose without fear of disruption or disconnection. When this time expires, however, the device must return to the DHCP server to request a new IP address. When this happens, the device will have limited connectivity until it receives a new lease from the DHCP Server and can no longer communicate with other devices on the network that require static IP addresses.
The client’s computer must renew its current lease before it expires in order for it not to lose an active connection to the network. In this way, DHCP servers ensure that all devices using a particular IP address are “alive” and connected to the network at all times.
How do I fix the DHCP server not responding?
DHCP servers are mainly used to dynamically allocate IP addresses for devices that request one, but they can also be configured in failover setups. If the primary DHCP server fails or goes offline, then you should configure your router with another DHCP server as a backup so it takes over immediately and continues granting leases.
If you’re configuring your router as the secondary DHCP server, then you should go to LAN settings and enable “DHCP” or “Dynamic Host Configuration Protocol.” Enter the IP address of the primary DHCP server in order for your router to receive a list of available leases.
If there are no other DHCP servers on your network, then many routers will default back to a “manual” IP address setup. In this case, you will need to access the router’s management interface and enter a specific value for your device manually. This option is typically available as an alternative configuration in most routers that support DHCP failover settings.
Why do I have multiple DHCP servers?
In installations with several subnets, it may be necessary to have multiple DHCP servers. Each of these servers is responsible for a specific subnet or network segment, and provides IP addresses only on the local area it serves.
If your router’s LAN configuration allows you to assign static IPs within certain ranges, then you can reserve an address for each connected device so that they always receive the same IP address each time they connect. This is helpful if you are configuring a home network with shared resources, such as printers or storage devices accessible by all connected computers.
Conclusion
When a client requests an IP address, the DHCP Server checks its pool of available addresses and assigns one to that client for a specific length of time called a lease. If the DHCP Server is unable to give an IP address, it will update the client with a specific message. keep your DHCP server up to date.
