Configuring Option 82 - H3C MSR 2600 Configuration Manual

Step
4. Specify the port as a trusted
port.
5. Return to system view.
6. Enter interface view.
7. (Optional.) Enable recording
of DHCP snooping entries.

Configuring Option 82

Follow these guidelines when you configure Option 82:
To support Option 82, you must configure Option 82 on both the DHCP server and the DHCP
•
snooping device. For information about configuring Option 82 on the DHCP server, see
handling of Option
• If the handling strategy is configured as replace, you must configure a padding format for Option
82. If the handling strategy is keep or drop, there is no need to configure any padding format.
If Option 82 contains the device name, the device name must contain no spaces. Otherwise, DHCP
•
snooping drops the message. You can use the sysname command to specify the device name. For
more information about this command, see Fundamentals Command Reference.
• If DHCP snooping and QinQ work together or DHCP snooping receives a DHCP packet with two
VLAN tags, and the verbose padding format is adopted for Option 82, DHCP snooping fills the
VLAN ID field of sub-option 1 with outer VLAN tag.inner VLAN tag. For example, if the outer VLAN
tag is 10 (a in hexadecimal) and the inner VLAN tag is 20 (14 in hexadecimal), the VLAN ID is
000a.0014.
To configure DHCP snooping to support Option 82:
Step
1. Enter system view.
2. Enter interface view.
3. Enable DHCP snooping to
support Option 82.
4. (Optional.) Configure a
handling strategy for DHCP
requests that contain Option
82.
5. (Optional.) Configure the
padding content and code
type for the circuit ID
sub-option.
Command
dhcp snooping trust
quit
interface interface-type
interface-number
dhcp snooping binding record
82."
Command
system-view
interface interface-type interface-number
dhcp snooping information enable
dhcp snooping information strategy { drop
| keep | replace }
dhcp snooping information circuit-id
{ [ vlan vlan-id ] string circuit-id | { normal |
verbose [ node-identifier { mac | sysname
| user-defined node-identifier } ] } [ format
{ ascii | hex } ] }
72
Remarks
By default, all ports are untrusted
ports after DHCP snooping is
enabled.
N/A
This interface must connect to the
DHCP client.
By default, after DHCP snooping is
enabled, recording of DHCP
snooping entries is disabled.
Remarks
N/A
N/A
By default, DHCP snooping
does not support Option
82.
By default, the handling
strategy is replace.
By default, the padding
format is normal and the
code type is hex for the
circuit ID sub-option.
"Enabling