To configure the DHCP snooping binding database agent, use the ip dhcp snooping database Global Configuration mode command.
To disable the agent, reset the timeout value, or reset the write-delay value, use the no form of this command.
Syntax
ip dhcp snooping database {flash | tftp {IPv4-ADDR NAME | HOSTNAME NAME} | timeout VALUE | write-delay VALUE }
no ip dhcp snooping database [timeout | write-delay]
Parameters
flash—Specifies that the database agent is in the flash memory.
tftp IPv4-ADDR NAME—Specifies the IP address of the remote TFTP server and the file name of the backup file.
tftp HOSTNAME NAME—Specifies the hostname of the remote TFTP server and the file name of the backup file.
timeout VALUE—Specifies the timeout in seconds when to stop the database transfer process after the DHCP snooping binding database changes.
(Range: 0 to 86400 seconds. Use 0 to define an infinite duration.)
write-delay VALUE—Specifies the duration in seconds for which the transfer should be delayed after the binding database changes. (Range: 15
to 86400 seconds)
Default Configuration
The URL for the database agent is not defined.
The default timeout is 300 seconds (5 minutes).
The default write-delay is 300 seconds (5 minutes).
Command Mode
Global Configuration mode
User Guidelines
The DHCP snooping binding database can have up to 256 bindings. Because both NVRAM and flash memory have limited storage capacity,
we recommend that you store a binding file on a TFTP server. You must create an empty file at the configured URL on network-based
URLs (such as TFTP and FTP) before the switch can write bindings to the binding file at that URL for the first time.
To save the DHCP snooping binding database in the switch NVRAM, use the ip dhcp snooping database flash command.
To disable the agent, use the no ip dhcp snooping database command.
To reset the timeout value, use the no ip dhcp snooping database timeout command.
To reset the write-delay value, use the no ip dhcp snooping database write-delay command.
Example
switchxxxxxx(config)# ip dhcp snooping database flash
switchxxxxxx(config)# ip dhcp snooping database tftp 192.168.1.20 test1
switchxxxxxx(config)# ip dhcp snooping database tftp test-host test2
switchxxxxxx(config)# ip dhcp snooping database timeout 1200
switchxxxxxx(config)# ip dhcp snooping database write-delay 3000