H3C Technologies H3C S10500 Series Switches - Manual (Page 86)

75
To do… Use the command… Remarks
Enter interface view interface interface-type interface-number —
Enable DHCP snooping to support
Option 82
dhcp-snooping information enable
Required
Disabled by default.
Configure the handling strategy for
requests containing Option 82 dhcp-snooping information strategy
{ drop | keep | replace } Optional
replace by default.
Configure the
padding format for
Option 82
dhcp-snooping information format
{ normal | verbose [ node-identifier { mac
| sysname | user-defined
node-identifier } ] }
Optional
normal by default.
Configure the code
type for the circuit
ID sub-option
dhcp-snooping information circuit-id
format-type { ascii | hex }
Optional
By default, the code
type depends on the
padding format of
Option 82. Each field
has its own code type.
This code type
configuration applies
to non-user-defined
Option 82 only.
Configure Option
82 in the normal or
verbose padding
format
Configure the code
type for the remote
ID sub-option
dhcp-snooping information remote-id
format-type { ascii | hex }
Optional
hex by default.
The code type
configuration applies
to non-user-defined
Option 82 only.
Configure the
padding content
for the circuit ID
sub-option
dhcp-snooping information [ vlan
vlan-id ] circuit-id string circuit-id
Optional
By default, the
padding content
depends on the
padding format of
Option 82.
Configure
user-defined
Option 82
Configure the
padding content
for the remote ID
sub-option
dhcp-snooping information [ vlan
vlan-id ] remote-id string { remote-id |
sysname }
Optional
By default, the
padding content
depends on the
padding format of
Option 82.
Configuring DHCP snooping entries backup
DHCP snooping entries cannot survive a reboot. If the DHCP snooping device is rebooted, security
modules (such as IP source guard) that use DHCP snooping entries to authenticate users will reject
requests from clients until new entries are learned.
The DHCP snooping entries backup feature enables you to store DHCP snooping entries in a file. When
the DHCP snooping device reboots, it reads DHCP snooping entries from this file.