H3C Technologies H3C S5120 Series Switches - Manual (Page 259)

3-6
To do… Use the command… Remarks
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.
z You can enable DHCP snooping to support Option 82 on Layer 2 Ethernet interfaces and Layer 2
aggregation interfaces only.
z If a Layer 2 Ethernet interface is added to an aggregation group, enabling DHCP snooping to
support Option 82 on the interface will not take effect. After the interface quits the aggregation
group, the configuration will be effective.
z If the handling strategy of the DHCP-snooping-enabled device is configured as replace, you need
to configure a padding format for Option 82. If the handling strategy is keep or drop, you need not
configure any padding format.
z If the Option 82 is padded with the device name (sysname) of a node, the device name must
contain no spaces. Otherwise, the DHCP-snooping-enabled device will drop the message.
Displaying and Maintaining DHCP Snooping
To do… Use the command… Remarks
Display DHCP snooping entries
display dhcp-snooping [ ip
ip-address ]
Available in any view
Display Option 82 configuration
information on the DHCP snooping
device display dhcp-snooping
information { all | interface
interface-type interface-number }
Available in any view
Display DHCP packet statistics on the
DHCP snooping device display dhcp-snooping packet
statistics
Available in any view
Display information about trusted ports display dhcp-snooping trust Available in any view