What Is DHCP (Dynamic Host Configuration Protocol)?

Q: What is DHCP and how does it work?

DHCP, the Dynamic Host Configuration Protocol, automatically assigns an IP address and network settings to every device that joins a network. A DHCP server, usually built into the router, holds a pool of addresses and gives one to each device that asks, along with the subnet mask, gateway, and DNS servers. This removes the need to configure addresses by hand.

Q: What is a DHCP lease?

A DHCP lease is the temporary assignment of an address to a device for a limited time. The device renews the lease before it expires, usually keeping the same address, and if a device leaves and the lease lapses the address can return to the pool. Lease duration is configurable and commonly ranges from hours to days depending on the network.

Q: What is the difference between DHCP and a static IP address?

A static IP is set manually on the device and never changes, while a DHCP address is assigned dynamically and managed centrally. DHCP suits ordinary devices because it is automatic and avoids conflicts, whereas a static address suits something that must be found reliably, like a printer or server. A DHCP reservation can give a device a fixed address while still being centrally managed.

Q: What is the DHCP DORA process?

DORA is the four-step exchange DHCP uses to assign an address: Discover, where the device broadcasts a request, Offer, where a server offers an available address, Request, where the device asks to take that address, and Acknowledge, where the server confirms the assignment. DHCP uses UDP with the server on port 67 and the client on port 68.

Q: Should I turn off DHCP on my router?

For almost all home networks, no. DHCP is what lets devices connect effortlessly, and turning it off means configuring every device by hand, which invites mistakes and address conflicts. The main reason to disable it is to avoid running two DHCP servers on one network, such as when adding a second router. Otherwise leaving DHCP on is the right default.

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How Devices Get an IP Address Automatically
When a phone or laptop joins a network, it needs an IP address, a subnet mask, a default gateway, and DNS servers before it can do anything. DHCP, the Dynamic Host Configuration Protocol, hands out all of that automatically. A DHCP server, usually built into your home router, keeps a pool of addresses and assigns one to each device that asks, so nobody has to configure addresses by hand. This is why you can connect to almost any Wi-Fi and just work.
The public address your router itself presents to the internet is separate from the private one DHCP gives your device on the LAN. You can see that public address on our IP Lookup and on the home page.
The DORA Process
DHCP assigns an address through a four-step exchange known as DORA: Discover (the new device broadcasts a request for an address), Offer (a DHCP server replies offering an available address), Request (the device asks to take that specific offered address), and Acknowledge (the server confirms and records the assignment). DHCP uses UDP, with the server on port 67 and the client on port 68. After DORA completes, the device has a working address and the settings it needs.
What Is a DHCP Lease?
An address from DHCP is not permanent, it is a lease for a limited time. Before the lease expires the device renews it, usually keeping the same address. If a device leaves and the lease lapses, that address can return to the pool for another device. Lease duration is configurable by the network administrator and commonly ranges from hours to days depending on the network. Leasing is what lets a network with a limited pool serve many devices that come and go.
DHCP vs a Static IP
A static IP is set manually on the device and never changes, while a DHCP-assigned address is dynamic and managed centrally. DHCP is ideal for ordinary devices because it is automatic and avoids address conflicts. A static address is useful for something that other devices need to find reliably, like a printer, a NAS, or a server you are forwarding a port to. Many routers offer a middle ground called a DHCP reservation, where the server always hands the same device the same address, giving static-like stability with central management.
Should You Turn Off DHCP?
For almost all home networks, no. DHCP is what makes devices connect effortlessly, and disabling it means configuring every device by hand, which invites mistakes and address conflicts. The main reason to disable it is to avoid running two DHCP servers on the same network, for example when you add a second router and want the first one to keep handing out addresses. Outside that case, leaving DHCP on is the right default.
Frequently Asked Questions
What is DHCP and how does it work?
DHCP, the Dynamic Host Configuration Protocol, automatically assigns an IP address and network settings to every device that joins a network. A DHCP server, usually built into the router, holds a pool of addresses and gives one to each device that asks, along with the subnet mask, gateway, and DNS servers. This removes the need to configure addresses by hand.
What is a DHCP lease?
A DHCP lease is the temporary assignment of an address to a device for a limited time. The device renews the lease before it expires, usually keeping the same address, and if a device leaves and the lease lapses the address can return to the pool. Lease duration is configurable and commonly ranges from hours to days depending on the network.
What is the difference between DHCP and a static IP address?
A static IP is set manually on the device and never changes, while a DHCP address is assigned dynamically and managed centrally. DHCP suits ordinary devices because it is automatic and avoids conflicts, whereas a static address suits something that must be found reliably, like a printer or server. A DHCP reservation can give a device a fixed address while still being centrally managed.
What is the DHCP DORA process?
DORA is the four-step exchange DHCP uses to assign an address: Discover, where the device broadcasts a request, Offer, where a server offers an available address, Request, where the device asks to take that address, and Acknowledge, where the server confirms the assignment. DHCP uses UDP with the server on port 67 and the client on port 68.
Should I turn off DHCP on my router?
For almost all home networks, no. DHCP is what lets devices connect effortlessly, and turning it off means configuring every device by hand, which invites mistakes and address conflicts. The main reason to disable it is to avoid running two DHCP servers on one network, such as when adding a second router. Otherwise leaving DHCP on is the right default.
Last updated: April 2026