What is DHCP lease time and how to change it?

When you connect to a local network, via WiFi or Ethernet, a DHCP (Dynamic Host Configuration Protocol) server on your network router will give your device an IP address. This gives your device an ID that allows other devices to locate and connect to it. Usually this IP address takes about 24 hours to expire.

This is due to the DHCP lease time. This allows a local area network to reassign IP addresses of devices that have been disconnected from other devices for a while, freeing up IP addresses for other devices to connect (unless you give them a Static ip

What is DHCP lease time and should it be changed?

Unless otherwise noted, a typical network router assumes that any connection made to it is temporary. Your device is assigned an IP by the DHCP server that has a lease time associated with it. If your device is not seen after that period has expired, the lease will expire and the IP address will be released for use by other devices.

The DHCP lease time is the time a lease allows to remain active before it expires. As we mentioned, 24 hours is the usual lease time given by networks for connected devices, but this is a default value that may not be appropriate for your network.

However, you can change this value. If you use an open or public network that others can connect to, you can expect a large number of short-term connections. This is where a shorter lease time would make sense, replenishing the pool of free IP addresses and allowing new devices to connect.

The lease time you use depends on your own needs. For example, you can use an hour for a restaurant WiFi network up to 12 hours for a guest office network.

You need administrator access to your network router to change these settings. While you can view the current DHCP lease time on your PC or Mac, changing it requires access to your router.

View DHCP lease time on Windows 10

You can view the DHCP lease time for a Windows PC using the Windows PowerShellthe replacement for the command line on Windows 10.

  • To open a PowerShell window, right-click on the Windows Start menu and press Windows PowerShell (administrator)† This will launch a PowerShell terminal with administrator privileges.
  • In the PowerShell window, type ipconfig /all† It contains all relevant information about your current network connections, including your DHCP lease issue and expiration times. For your network adapter, search for the Lease obtained and Lease expires values.

You can determine the lease time based on this information. In the example above, the lease expiration time is exactly 24 hours after the lease is first issued. This period may be shorter or longer for your connection, depending on your own network configuration.

View DHCP lease time on macOS

On a Mac, you can view the DHCP lease time using the built-in Terminal app.

  • You can launch the Terminal app by clicking Launchpad > Other > Terminal from the Dock at the bottom of your screen.
  • You need to know the device name of your network device on macOS. To do this, type networksetup -listallhardwareports in the Terminal window and press enter. Displays the name and MAC address for all network devices.
  • Once you have your device name, you can find the current DHCP lease time by typing ipconfig getpacket en0substitute nl0 with your own device name. This will display various information about your connection. The DHCP lease time is displayed next to the lease_time(uint32) choice.

The DHCP lease time is shown here as a base-16 hexadecimal value. you will have to convert these values to a standard decimal number. For example, the above connection has a hexadecimal DHCP lease value of 0x15180† This one converts to 86400the length of the lease in seconds, which is equal to 24 hours

Changing DHCP lease times on a local network

It is not possible to change the DHCP lease time in your device’s network settings as it is managed by the DHCP server that assigns IP addresses, which is usually your network router. You need administrator access to your router to change this.

You can usually connect to your network router by typing or in a web browser while connected to the network. You may need to check your router’s manual to determine if this is the correct way to connect, as well as the administrator’s username and password to log in.

After you sign up, you need to look for the right one Network/LAN Settings or DHCP Settings area in your router’s settings menu. If you can’t find it, see your owner’s manual for more advice.

The DHCP lease value is named in several ways. For example, on a TP-Link router, this value will be the address lease time† You can set this in minutes for this type of router, up to a maximum of 2880 (the equivalent of 48 hours† Other routers have longer or shorter maximum lease periods.

Change the value accordingly and save your settings. After the DHCP lease value is changed, the new lease time will be provided to your devices accordingly.

Renew a DHCP lease?

If you have changed your DHCP lease time, you can force all connected devices to release and renew the existing IP lease. This allows any changes to your DHCP lease information to be applied immediately.

  • To do this on a Windows 10 PC, open a Windows PowerShell window by right-clicking the Start menu and pressing Windows PowerShell (Administrator)
  • In the PowerShell window that opens, type ipconfig /release† This releases the existing IP lease and disconnects.
  • Type ipconfig /renew to reestablish the connection. The network’s DHCP server will issue a new lease at this point.
  • On macOS, you can do this through the System Preferences menu. press the apple icon on the menu bar, then click System Preferences
  • In the System Preferences menu, press Network† Select your network connection in the left menu, then press Advanced
  • In the Advanced Network menu, press the TCP/IP tab. Click on the Renew DHCP lease button to automatically release and renew your IP lease.

This will take a few seconds to complete. Once completed, your IP address will be updated to confirm your IP address, but you need to run ipconfig getpacket en0 (replacing nl0 with your own connection) from the Terminal app to view the current lease time.

Proper network management in Windows 10

The DHCP lease time assigned to devices on a network is an essential part of how your network works. If you struggle with IP address conflictsbut maybe you think it’s better to assign a static IP address to devices that you use regularly.

Many of these settings must be configured on your network router, but Windows allows you to change the network settings yourself. Be prepared for conflicts if your settings do not match your router. This can prevent you from seeing other computers on your network, so check any settings you change first.

Leave a Reply

Your email address will not be published.