send forcerenew

Function

The send forcerenew command enables a DHCP server to send FORCERENEW messages.

Format

send forcerenew section sectionNum [ ip startIp [ endIp ] ] [ recycle ]

Parameters

Parameter	Description	Value
ip startIp	Specifies the start IP address of an address segment.	The value is in dotted decimal notation.
endIp	Specifies the end IP address of an address segment. The end IP address must be greater than or equal to the start IP address. If the end IP address is not specified, there is only one IP address in the address segment.	The value is in dotted decimal notation.
recycle	Indicates the address recycling flag. If this parameter is specified, the DHCP server reclaims the corresponding IP address if it does not receive a response from a DHCP client.	-
section sectionNum	Specifies the number of an address segment.	The value is an integer ranging from 0 to 255.

Views

IP address pool view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
dhcp	execute

Usage Guidelines

Usage Scenario

To force a DHCP client to enter the RENEW state, configure a DHCP server to send a unicast FORCERENEW message to the client.

When the DHCP client attempts to renew its lease by unicasting a DHCPREQUEST message to the DHCP server according to the DHCP lease renewal process: If the DHCP server replies with a DHCPACK message, the lease is successfully renewed. If the DHCP server replies with a DHCPNAK message, the DHCP client needs to re-initiate a request.
When the DHCP server does not receive any response from the DHCP client for a period of time: If address recycling is configured, the server reclaims the corresponding IP address. Otherwise, the server reclaims the IP address when the lease expires, but not when it receives no response in the period.
For example, if a client has gone offline unexpectedly, after you configure the DHCP server to send FORCERENEW messages, it unicasts a FORCERENEW message to the client; however, it does not receive any response from the client. In this case, if address recycling is configured, the server will reclaim the corresponding IP address, implementing efficient allocation of IP addresses.

Precautions

If you run this command again before the DHCP server sends out all FORCERENEW messages, the system displays an error message.
To stop the server from sending FORCERENEW messages, run the stop send forcerenew command.

Example

# Enable a DHCP server to send FORCERENEW messages for address segment 1 with the start IP address of 10.1.1.1 and the end IP address of 10.1.1.255 in an address pool named huawei.

<HUAWEI> system-view
[~HUAWEI] ip pool huawei server
[*HUAWEI-ip-pool-huawei] gateway 10.1.1.1 255.255.255.0
[*HUAWEI-ip-pool-huawei] section 1 10.1.1.1 10.1.1.255
[*HUAWEI-ip-pool-huawei] send forcerenew section 1 ip 10.1.1.1 10.1.1.255