3-4
Figure 3-5
Standard format of the remote ID sub-option
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
Figure 3-6
.
Figure 3-6
Ways of handling a DHCP packet with Option 82
Handling
policy
Sub-option
configuration
The DHCP Snooping device will…
Drop
—
Drop the packet.
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
Figure 3-7
.
Figure 3-7
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.
Содержание S3100 Series
Страница 12: ...10 You can e mail your comments about product documentation to info h3c com We appreciate your comments...
Страница 74: ...7 7 Sysname ip http acl 2030...
Страница 270: ...1 51 Sysname GigabitEthernet1 0 1 port trunk permit vlan all...
Страница 287: ...1 14 the interface on which the packet actually arrived The RPF check succeeds and the packet is forwarded...
Страница 579: ...ii Configuration Example 2 4 QoS Profile Configuration Example 2 4...
Страница 713: ...1 22 Total associations 1...
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Страница 1054: ...i Table of Contents Appendix A Acronyms A 1...