dhcp server lease

Function

The dhcp server lease command specifies the IP address lease for addresses in an interface address pool.

The undo dhcp server lease command restores the default IP address lease of addresses in an interface address pool.

By default, the IP address lease of addresses in an interface address pool is one day.

Format

dhcp server lease { day day [ hour hour [ minute minute ] ] | unlimited }

undo dhcp server lease

Parameters

Parameter	Description	Value
day day	Specifies the number of days in the IP address lease.	The value is an integer that ranges from 0 to 999. The default value is 1.
hour hour	Specifies the number of hours in the IP address lease.	The value is an integer that ranges from 0 to 23. The default value is 0.
minute minute	Specifies the number of minutes in the IP address lease.	The value is an integer that ranges from 0 to 59. The default value is 0.
unlimited	Indicates that the IP address lease is unlimited.	-

Views

Interface view

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

This command applies to DHCP servers. To meet different client requirements, DHCP supports dynamic, automatic, and static address assignment.

DHCP clients require different IP address leases.

If a host (such as the DNS server) needs to use a fixed IP address for a long time, run the dhcp server lease unlimited command to configure the IP address lease as unlimited.
If a host (such as a portable computer) needs to use a temporary IP address, run the dhcp server lease command to specify an IP address lease. After the lease expires, the DHCP server withdraws the IP address and assigns the address to other clients.

When a DHCP client starts and 50% or 87.5% of its IP address lease has passed, the DHCP client sends a DHCP Request message to the DHCP server to renew the lease.

If the IP address can still be assigned to the client, the DHCP server informs the client of a renewed IP address lease.
If the IP address can no longer be assigned to the client, the DHCP server informs the client that the IP address lease cannot be renewed.

You can run the display ip pool command to view information about the IP address lease. The values of the lease and left fields in the command output indicate the configured lease time and remaining lease time, respectively.

Prerequisites

The DHCP function has been enabled using the dhcp enable command in the system view.
IP addresses in the interface address pool have been configured using the ip address command.
The DHCP server function has been enabled on the interface using the dhcp select interface command.

Precautions

Different IP address leases can be specified for different interface address pools on a DHCP server. All IP addresses in an interface address pool have the same lease.

If the IP address lease of an address pool is changed using this command, newly assigned IP addresses use the new IP address lease. IP addresses assigned before the change still use the original IP address lease before the lease is updated, and use the new lease after the lease is updated.

Example

# Set the IP address lease of the address pool on VLANIF100 to 2 days 2 hours and 30 minutes.

<HUAWEI> system-view
[HUAWEI] dhcp enable
[HUAWEI] interface vlanif 100
[HUAWEI-Vlanif100] ip address 10.10.10.10 24 
[HUAWEI-Vlanif100] dhcp select interface
[HUAWEI-Vlanif100] dhcp server lease day 2 hour 2 minute 30

# Set the IP address lease of the address pool on GE0/0/1 to 2 days 2 hours and 30 minutes.

<HUAWEI> system-view
[HUAWEI] dhcp enable
[HUAWEI] interface gigabitethernet 0/0/1
[HUAWEI-GigabitEthernet0/0/1] undo portswitch
[HUAWEI-GigabitEthernet0/0/1] ip address 10.10.10.10 24 
[HUAWEI-GigabitEthernet0/0/1] dhcp select interface
[HUAWEI-GigabitEthernet0/0/1] dhcp server lease day 2 hour 2 minute 30