What Is DHCP Lease Time And How To Change It

What Is DHCP Lease Time And How To Change It

When you connect to your local network via WiFi or Ethernet, the DHCP (Dynamic Host Configuration Protocol) server on your network router will give your device an IP address. This gives your device an identifier that allows other devices to find it and connect to it. Typically, this IP address is valid for about 24 hours before it expires.

This is due to the timing of the DHCP lease. This allows the LAN to redistribute IP addresses from devices that have been disconnected for a while to other devices, freeing up IP addresses for other devices that can connect (unless you give them a static IP address).

What is the DHCP lease time and should it be changed?

Unless otherwise noted, a typical network router assumes that any connection to it is temporary. Your device is assigned an IP address by a DHCP server with an associated lease. If after this period your device is not visible, the lease expires and the IP address is released for use by other devices.

The DHCP lease time is the time that a lease remains active before it expires. As we already mentioned, 24 hours is the usual lease period provided by networks for connected devices, but this is a standard value and may not be suitable for your network.

However, you can change this value. If you are using an open or public network that other users can connect to, you can expect a lot of short-term connections. This is where it makes sense to shorten the lease time while keeping the pool of free IP addresses replenished and allowing new devices to connect.

The rental period depends on your needs. For example, you can use an hour for a WiFi network in a restaurant and 12 hours for a guest office network.

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To change these settings, you will need administrative access to your network router. While you can view the current DHCP lease time on your PC or Mac, you will need access to your router to change it.

How to display DHCP Lease Time on Windows 10

You can view the DHCP lease times for Windows PCs using Windows PowerShell, a command line replacement in Windows 10.

• To open a PowerShell window, right-click the Windows Start menu. and click Windows PowerShell (Admin). This will launch a PowerShell terminal with administrator rights.

• In the PowerShell window, enter ipconfig / all. It will list all the information you need about your current network connections, including DHCP lease issue and expiration time. For your network adapter, find the Lease Obhibited and Lease Expires values.

With this information, you can determine the rental period. In the example above, the lease expires exactly 24 hours after the lease was first booked. This period may be shorter or longer for your connection, depending on your network configuration.

How to display DHCP Lease Duration on macOS

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

• You can launch the Terminal application by clicking Launchpad Other Terminal in the dock at the bottom of the screen.

• You need to know the name of your network device in macOS. To do this, type networksetup -listallhardwareports in the Terminal window and press Enter. It will list the names and MAC addresses of all network devices.

• Once you have your device name, you can find out the current DHCP lease time by typing ipconfig getpacket en0, replacing en0 with your own device name. It will list various information about your connection. The DHCP lease time will be listed next to the lease_time (uint32) parameter.

The DHCP lease times will be shown here as a base 16 hexadecimal value. You will need to convert these values
??to standard decimal. For example, the above connection has a DHCP lease hex value of 0x15180. This translates to 86400, the lease duration in seconds, which is equivalent to 24 hours.

Change DHCP lease times on a local network

It is not possible to change the DHCP lease time in your device’s network settings as this is controlled by a DHCP server that allocates IP addresses, which is usually your network router. To change this, you need administrative access to the router.

You can usually connect to your network router by typing http://192.168.1.1 or http://192.168.0.1 in your web browser while connected to the network. You may need to check the manual for your router to determine if this is the correct way to connect, and determine the admin username and password to login.

Once you are logged in, you will need to find the corresponding network / LAN settings or DHCP settings in the settings menu of your router. If you can’t find it, check your user manual for more tips.

The meaning of the DHCP lease is named differently. For example, on a TP-Link router, this value is called the address lease time. You can set this value in minutes for this type of router, up to a maximum of 2880 (equivalent to 48 hours). Other routers will have more or less maximum leases.

Change the value accordingly, then save the settings. After changing the DHCP lease value, your devices will be assigned a new lease time.

How to Renew a DHCP Lease

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

• On a Windows 10 PC, open a Windows PowerShell window by right-clicking the Start menu and clicking Windows PowerShell. (Administrator).

• With a PowerShell window open, enter ipconfig / release. This will release the existing IP lease and disconnect.

• Enter ipconfig / Renew to restore the connection. At this point, the network DHCP server will issue a new lease.

• On macOS, this can be done from the System Preferences menu. Click the Apple icon in the menu bar, then click System Preferences.

• From the System Preferences menu, click Network. Select your network connection from the left menu and click Advanced.

• From the Advanced Network menu, click the TCP / IP tab. Click the Renew DHCP Lease button to automatically release and renew the IP lease.

It will take a few seconds. Once complete, your IP will update to confirm your IP, but you will need to run ipconfig getpacket en0 (replacing en0 with your own connection) from the Terminal app to check your current lease time.

Corrected Network Administration in Windows 10

The DHCP lease time allocated to devices on the network is an important component of the operation of your network. However, if you are struggling with IP address conflicts, you may find that it is better to assign a static IP address to devices that you use regularly.

Many of these settings need to be configured on your network router, but Windows will let you change the network settings yourself – be prepared for conflicts if your settings don’t match your router. This can prevent you from seeing other computers on your network, so be sure to double check any settings you’ve changed first.

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What Is DHCP Lease Time And How To Change It