96
Step Command Remarks
5. (Optional.) Configure the
padding mode and padding
format 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
mode is
normal
and the
padding format is
hex
for
the Circuit ID sub-option.
6. (Optional.) Configure the
padding mode and padding
format 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
mode is
normal
and the
padding format is
hex
for
the Remote ID sub-option.
Configuring DHCP snooping entry auto backup
The auto backup feature saves DHCP snooping entries to a backup file, and allows the DHCP
snooping device to download the entries from the backup file at device reboot. The entries on the
DHCP 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 DHCP snooping entries for user
authentication.
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 backup file.
To save DHCP snooping entries:
Step Command Remarks
1. Enter system view.
system-view
N/A
2. Configure the DHCP
snooping device to back up
DHCP snooping entries to a
file.
dhcp snooping binding
database filename
{ filename |
url
url [
username
username
[
password
{
cipher
|
simple
}
string ] ] }
By default, the DHCP snooping
device does not back up DHCP
snooping entries.
With this command executed, the
DHCP snooping device backs up
DHCP snooping entries
immediately and runs auto backup.
This command automatically
creates the file if you specify a
non-existent file.
3. (Optional.) Manually save
DHCP snooping entries to
the backup file.
dhcp snooping binding
database update now
N/A
4. (Optional.) Set the waiting
time after a DHCP snooping
entry change for the DHCP
snooping device to update
the backup file.
dhcp snooping binding
database update interval
interval
The default waiting time is 300
seconds.
When a DHCP snooping entry is
learned, updated, or removed, the
waiting period starts. The DHCP
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.