H3C H3C S5100-SI, Operation Manual, Page: 358 / 830

3-4
Handling policy Sub-option configuration The DHCP Snooping device will…
Keep —
Forward the packet without changing
Option 82.
Neither of the two
sub-options is configured
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.
Circuit ID sub-option is
configured
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.
Replace
Remote ID sub-option is
configured
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.
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 3-2 .
Table 3-2 Ways of handling a DHCP packet without Option 82
Sub-option configuration The DHCP-Snooping device will …
Neither of the two sub-options is configured.
Forward the packet after adding Option 82 with
the default contents.
The format of Option 82 is the one specified with
the
dhcp-snooping information format
command or the default HEX format if this
command is not executed.
Circuit ID sub-option is configured.
Forward the packet after adding Option 82 with
the configured circuit ID sub-option in ASCII
format.
Remote ID sub-option is configured.
Forward the packet after adding Option 82 with
the configured remote ID sub-option in ASCII
format.
The circuit ID and remote ID sub-options in Option 82, which can be configured simultaneously or
separately, are independent of each other in terms of configuration sequence.
When the DHCP snooping device receives a DHCP response packet from the DHCP server, the DHCP
snooping device will delete the Option 82 field, if contained, before forwarding the packet, or will directly
forward the packet if the packet does not contain the Option 82 field.