Configuring DHCPv6 snooping entry auto backup

The auto backup feature saves DHCPv6 snooping entries to a backup file, and allows the DHCPv6 snooping device to download the entries from the backup file at reboot. The entries on the DHCPv6 snooping device cannot survive a reboot. The auto backup helps the security features provide services if these features (such as IP source guard) must use DHCPv6 snooping entries for user authentication.

• If you disable DHCPv6 snooping with the undo ipv6 dhcp snooping enable command, the device deletes all DHCPv6 snooping entries, including those stored in the backup file.

• If you execute the ipv6 dhcp snooping binding database filename command, the DHCPv6 snooping device backs up DHCPv6 snooping entries immediately and runs auto backup. This command automatically creates the file if you specify a non-existent file.

• The waiting period starts when a DHCPv6 snooping entry is learned, updated, or removed. The DHCPv6 snooping device updates the backup file when the specified waiting period is reached. All changed entries during the period will be saved to the backup file. If no DHCPv6 snooping entry changes, the backup file is not updated.

1. Enter system view.

   system-view

2. Configure the DHCPv6 snooping device to back up DHCPv6 snooping entries to a file.

   ipv6 dhcp snooping binding database filename { filename | url url [ username username [ password { cipher | simple } string ] ] }

   By default, the DHCPv6 snooping device does not back up the DHCPv6 snooping entries.

3. (Optional.) Manually save DHCPv6 snooping entries to the backup file.

   ipv6 dhcp snooping binding database update now

4. (Optional.) Set the waiting time after a DHCPv6 snooping entry change for the DHCPv6 snooping device to update the backup file.

   ipv6 dhcp snooping binding database update interval interval

   By default, the DHCP snooping device waits 300 seconds to update the backup file after a DHCP snooping entry change. If no DHCP snooping entry changes, the backup file is not updated.