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•  The VPN information of the DHCP server's interface that receives DHCP packets from the 
client. 
The VPN information from authentication modules takes priority over the VPN information of the 
receiving interface. 
To apply a DHCP address pool to a VPN instance: 
 
Step Command Remarks 
1.  Enter system view. 
system-view
 N/A 
2.  Create a DHCP address pool 
and enter its view. 
dhcp server ip-pool
 pool-name
 
By default, no DHCP address 
pool exists. 
3.  Apply the address pool to a 
VPN instance. 
vpn-instance
 vpn-instance-name
 
By default, no VPN instance is 
applied to the address pool. 
 
Enabling client offline detection on the DHCP 
server 
The client offline detection feature reclaims an assigned IP address and deletes the binding entry 
when the ARP entry for the IP address ages out. The feature does not function if an ARP entry is 
manually deleted. 
To enable client offline detection on the DHCP server: 
 
Step Command Remarks 
1.  Enter system view. 
system-view
 N/A 
2.  Enter interface view. 
interface 
interface-type 
interface-number
 
N/A 
3.  Enable client offline detection.
dhcp client-detect 
By default, client offline 
detection is disabled on the 
DHCP server. 
 
Enabling DHCP logging on the DHCP server 
The DHCP logging feature enables the DHCP server to generate DHCP logs and send them to the 
information center. For information about the log destination and output rule configuration in the 
information center, see Network Management and Monitoring Configuration Guide. 
As a best practice, disable this feature if the log generation affects the device performance or 
reduces the address allocation efficiency. For example, this situation might occur when a large 
number of clients frequently come online or go offline. 
To enable DHCP logging on the DHCP server: 
 
Step Command Remarks 
1.  Enter system view. 
system-view
 N/A 
2.  Enable DHCP logging. 
dhcp log enable 
By default, DHCP logging is 
disabled.