73Step Command Remarks6. (Optional.) Configure thepadding content and codetype for the remote IDsub-option.dhcp snooping information remote-id{ normal [ format { ascii | hex } ] | [ vlanvlan-id ] string remote-id | sysname }By default, the paddingformat is normal and thecode type is hex for theremote ID sub-option.Saving DHCP snooping entriesDHCP snooping entries cannot survive a reboot. If the DHCP snooping device is rebooted, securityfeatures (such as IP source guard) that use DHCP snooping entries to authenticate users reject requestsfrom clients until new entries are learned.To avoid this problem, you can save DHCP snooping entries in a file so that DHCP snooping can readDHCP snooping entries from this file during a reboot.NOTE:If you disable DHCP snooping with the undo dhcp snooping enable command, the device deletes allDHCP snooping entries, including those stored in the specified file.To save DHCP snooping entries:Step Command Remarks1. Enter system view. system-view N/A2. Specify a file to save DHCPsnooping entries.dhcp snooping binding databasefilename { filename | url url[ username username[ password { cipher | simple }key ] ] }By default, no file is specified.This command enables the device toimmediately save DHCP snoopingentries to the specified database file.If the file does not exist, the deviceautomatically creates the file. Thedevice does not update the file for aspecified amount of time after aDHCP snooping entry changes. Thedefault period is 300 seconds. Tochange the value, use the dhcpsnooping binding database updateinterval command.3. (Optional.) Manually saveDHCP snooping entries to thefile.dhcp snooping binding databaseupdate nowDHCP snooping entries are saved tothe database file each time thiscommand is executed.4. (Optional.) Set the amount oftime to wait after a DHCPsnooping entry changesbefore updating the databasefile.dhcp snooping binding databaseupdate interval secondsThe default setting is 300 seconds.When a DHCP snooping entry islearned or removed, the device doesnot update the database file untilafter the specified waiting period.All changed entries during thatperiod will be updated.
