DHCP Lease Time Explained: How Long IP Addresses Last

What is a DHCP lease?

DHCP stands for Dynamic Host Configuration Protocol. It is the system that lets a router hand out IP addresses to phones, laptops, TVs and other devices on the local network. A lease is the length of time the router says a device may keep that address before it has to ask again. The lease is not a physical property of the device or the router; it is a setting stored in the router's DHCP server and renewed through network messages. DHCP powers this process on most home networks.

Think of a lease like a reserved seat in a shared room. The router reserves a numeric address for a device for a limited time. Once the time ends, the address can go back into the pool for another device. Public and private IP addresses explain why the addresses inside your home are separate from the internet-facing address.

How a DHCP lease works

When a device joins your network, it sends a request for an address. The router answers by offering one and attaching a lease time. The device accepts, and from that moment it can use the address for the network conversations you expect. Near the end of the lease, the device usually asks to renew the same address. If the router agrees, the lease starts again. If the device is gone when the lease ends, the address becomes free.

Routers manage this process in the background. On most home routers, the default lease time is a preset value chosen by the manufacturer, and you can adjust it in the LAN or DHCP section of the router's admin page. To find that page, see how to log in to the router admin page.

• Lease assigned: device receives an IP address and lease duration.
• Lease renewal: device asks for the same address before the lease expires.
• Lease expired: address can be reused by another device.

Lease time versus DHCP reservation

A lease time and a DHCP reservation solve different problems. Lease time controls how long an address can be used before renewal. A DHCP reservation tells the router to always give the same device the same address, regardless of lease. You might use a reservation for a printer, a network drive or a game console. The lease still exists, but the device keeps getting the same address because the router has reserved it.

Reservations matter when you want a device to have a predictable address without setting a manual static IP on the device. You can create one in the DHCP settings. For step-by-step instructions, see how to set up a DHCP reservation on a router.

What lease time should you choose?

There is no single lease time that works for every home. If most of your devices stay on the network, a longer lease reduces the number of renewal messages and gives each device a stable address. If you host many guests or run a network with frequently changing devices, a shorter lease helps the router reuse addresses quickly. As advice, start with a moderate setting for normal family use and shorten it for guest Wi-Fi.

• Longer lease: fewer renewals, more stable address, good for home devices.
• Shorter lease: faster reuse, better for public or guest networks.
• Reservation plus long lease: useful for important devices that must always be reachable.

Does lease time affect Wi-Fi performance?

Changing the DHCP lease time will not make Wi-Fi faster. Wi-Fi performance depends on the wireless standard, radio bands, antennas, congestion and router hardware. Lease time only affects how long an IP address is held before renewal. A device with an active lease can still use the full speed of its connection. If you are choosing a new router, focus on the Wi-Fi generation and features. See Wi-Fi 6 explained or Wi-Fi 7 explained for the differences.

On the other hand, a very short lease can cause a device to lose its address during a long download or video call if it fails to renew in time. For most homes, the safest choice is to leave the lease time at the manufacturer default unless you have a specific reason to change it. If devices drop off the network, check router DHCP not assigning IPs for common causes.

How to change the lease time on a router

Log in to the router, open the LAN or DHCP settings, and look for a field called lease time, DHCP lease or address lease. The wording depends on the router's firmware. Change the value to the duration you want and save the settings. After a change, devices may keep their current address until the old lease expires, or they may renew sooner depending on the router. You do not need to restart the router.

Some routers let you set separate lease times for the main network and the guest network. That can be useful if you want a short lease for visitors and a longer, stable lease for family devices. For guidance on picking a router, see the router buying checklist and router security basics.

What to pick for your use

Questions

What is a DHCP lease time?

It is the amount of time a router lets a device keep an IP address before the device requests a new one. The lease time is a setting on the router, not a fixed property of Wi-Fi.

What happens when a DHCP lease expires?

The device must ask for an address again. If the router still has the address available, it may give the same one. If not, it gives a different address from the pool.

Does a longer DHCP lease time improve speed?

No. Lease time does not control throughput. A longer lease can make address assignment more stable, but the actual speed of your internet and Wi-Fi depends on other factors.

Should I use a short lease for guests?

Shorter leases can help a guest network reclaim addresses quickly when visitors leave. They do not replace a separate guest network, but they are a useful part of managing a busy network.

What is the difference between DHCP lease and DHCP reservation?

A lease is a time-based grant of an IP address. A reservation is a rule that the same device should always receive the same address. Reservations are helpful for printers and servers.

Can a device keep an IP address forever?

A DHCP lease is always time-based. You can make the duration very long, but the router still uses the lease concept to manage address reuse. For a permanent address, use a DHCP reservation instead.