H3C Technologies H3C S12500 Series Switches - Manual (Page 76)

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Step Command Remarks
4. (Optional.) Configure a
handling strategy for DHCP
requests containing Option
82.
dhcp snooping information strategy { drop
| keep | replace } By default, the handling
strategy is replace.
5. (Optional.) Configure the
padding content and code
type for the circuit ID
sub-option.
dhcp snooping information circuit-id
{ [ vlan vlan-id ] string circuit-id | { normal |
verbose [ node-identifier { mac | sysname
| user-defined node-identifier } ] } [ format
{ ascii | hex } ] }
By default, the padding
format is normal and the
code type is hex for the
circuit ID sub-option.
6. (Optional.) Configure the
padding content and code
type for the remote ID
sub-option.
dhcp snooping information remote-id
{ normal [ format { ascii | hex } ] | [ vlan
vlan-id ] string remote-id | sysname }
By default, the padding
format is normal and the
code type is hex for the
remote ID sub-option.
75B
Saving DHCP snooping entries
DHCP snooping entries cannot survive a reboot. If the DHCP snooping device is rebooted, security
features (such as IP source guard) that use DHCP snooping entries to authenticate users reject requests
from clients until new entries are learned.
To avoid this problem, you can save DHCP snooping entries in a file so that DHCP snooping can read
DHCP snooping entries from this file during a reboot.
NOTE:
If you disable DHCP snooping with the undo dhcp snooping enable command, the device deletes all
DHCP snooping entries, including those stored in the specified file.
To save DHCP snooping entries:
Step Command Remarks
1. Enter system view. system-view N/A
2. Specify a file to save DHCP
snooping entries. dhcp snooping binding database
filename filename
By default, no file is specified.
DHCP snooping entries are saved to
the specified file after you execute
this command and are updated at
the interval set by the dhcp snooping
binding database update interval
command.
3. (Optional.) Manually save
DHCP snooping entries to the
file.
dhcp snooping binding database
update now
DHCP snooping entries are saved to
the file each time this command is
executed.
4. (Optional.) Set the interval at
which DHCP snooping entries
are saved to the file.
dhcp snooping binding database
update interval seconds
The default interval is 300 seconds.