H3C S3100-52P Operation Manual page 495

Operation Manual – DHCP
H3C S3100-52P Ethernet Switch
Figure 2-5 Standard format of the remote ID sub-option
III. Mechanism of DHCP-snooping Option 82
With DHCP snooping and DHCP-snooping Option 82 support enabled, when the
DHCP snooping device receives a DHCP client's request containing Option 82, it will
handle the packet according to the handling policy and the configured contents in
sub-options. For details, see
Table 2-1 Ways of handling a DHCP packet with Option 82
Handling
policy
Drop
Keep
Replace
When receiving a DHCP client's request without Option 82, the DHCP snooping device
will add the option field with the configured sub-option and then forward the packet. For
details, see
Table 2-1.
Sub-option
configuration
—
—
Neither of the
two sub-options
is configured
Circuit ID
sub-option is
configured
Remote ID
sub-option is
configured
Table 2-2.
Chapter 2 DHCP Snooping Configuration
The DHCP Snooping device will...
Drop the packet.
Forward the packet without changing Option 82.
Forward the packet after replacing the original
Option 82 with the default content.
The storage format of Option 82 content is the one
specified with the dhcp-snooping information
format command or the default HEX format if this
command is not executed.
Forward the packet after replacing the circuit ID
sub-option of the original Option 82 with the
configured circuit ID sub-option in ASCII format.
Forward the packet after replacing the remote ID
sub-option of the original Option 82 with the
configured remote ID sub-option in ASCII format.
2-4