H3C S5100-SI Series Operation Manual page 408

Operation Manual – DHCP
H3C S5100-SI/EI Series Ethernet Switches
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
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
2-1.
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