2-25 
If a DHCP server is configured to ignore Option 82, after the DHCP server receives packets containing 
Option 82, the DHCP server will not add Option 82 into the responses when assigning IP addresses and 
other configuration information to the clients.  
Follow these steps to configure the DHCP server to process Option 82: 
To do…  Use the command…  Remarks 
Enter system view 
system-view 
— 
Enable the DHCP server to 
process Option 82 
dhcp server relay 
information enable 
Optional 
By default, the DHCP server 
supports Option 82. 
 
Displaying and Maintaining the DHCP Server 
To do…  Use the command…  Remarks 
Display the statistics on IP 
address conflicts 
display dhcp server conflict { all | ip 
ip-address } 
Display lease expiration 
information 
display dhcp server expired { ip ip-address | 
pool [ pool-name ] | interface [ interface-type 
interface-number ] | all } 
Display the free IP addresses 
display dhcp server free-ip 
Display information about 
address binding 
display dhcp server ip-in-use { ip ip-address | 
pool [ pool-name ] | interface [ interface-type 
interface-number ] | all } 
Display the statistics on a 
DHCP server 
display dhcp server statistics 
Display information about 
DHCP address pool tree 
display dhcp server tree { pool [ pool-name ] | 
interface [ interface-type interface-number ] | 
all } 
Available in 
any view 
Clear IP address conflict 
statistics 
reset dhcp server conflict { all | ip ip-address } 
Clear dynamic address binding 
information 
reset dhcp server ip-in-use { ip ip-address | 
pool [ pool-name ] | interface [ interface-type 
interface-number ] | all } 
Clear the statistics on a DHCP 
server 
reset dhcp server statistics 
Available in 
user view 
 
 
Executing the save command will not save the lease information on a DHCP server to the flash memory. 
Therefore, the configuration file contains no lease information after the DHCP server restarts or you 
clear the lease information by executing the reset dhcp server ip-in-use command. In this case, any 
lease-update requests will be denied, and the clients must apply for IP addresses again.